Very high water consumption

[JX350C]

Hi everyone,

I moved into a new build three bedroom, two bathroom bungalow about 2.5 years ago. Ever since we moved in there has been an issue with the water pressure.

Toward the end of last year the pressure had got worse. For instance, you could not run another tap in the house if a toilet was refilling or if someone was in the shower. If someone was running a bath then all taps in the house would have no water supply to them and the toilets wouldn't refill if flushed until the bath was stopped.

So we telephoned our water provider to see if this is normal for this area or if there were any known issues with the supply in our street.

To our suprise they said that they have noticed that since we have moved into the property that we have been using very high amounts of water.

I can't see us consciously being users of a large amount of water. We have a shower most days and sometimes have a bath instead. We have a dishwasher and washing machine. The dishwasher is used about once a day and the washing machine is only used maybe twice a week at most. The showers we have are mixer type without any power assistance.

The water company have so far been very helpful and asked us to undertake some simple tests to try to identify either a leak or something else in the house using large amounts of water.

The first thing they asked us to do was to ensure the stopcock in the house was fully open. To my surprise I found the stopcock in the house to be only about half open. I thought that when we moved in that this was all setup correctly. I did check the stopcock before calling the water company but I could not turn it. After checking it again following speaking to the water company I managed to turn it until it was fully open. I think it had got a little seized so just needed more brute force to open it fully. Once I had opened it fully, we had full water pressure and we could use the taps at the same time as running a bath or flushing the toilet. The water that came out of the taps and toilet however was brown for a while and it then settled back to clear water.

So the water pressure issue was resolved.

But the water company stated we were using very large amounts of water so we needed to test for a leak between the meter in the street and the stopcock in the house.

So I fully turned off the stopcock and took a meter reading. I waited an hour and checked the meter again and it had not changed. So the water usage was from something or a leak in the house.

So I turned the stopcock fully open again and started to monitor usage by taking regular meter readings.

To my horror I could not believe the difference between the meter readings. Between the readings we did not use any toilets, showers, didn't have any baths and did not have the washing machine or dishwasher on. We didn't use any of the taps so I thought the readings should not change.

The first meter reading that I took, after opening the stopcock in full, was from overnight and it indicated that we had used 130 litres of water overnight.

I've been doing further readings with the stopvalves to individual items closed and without using any water from taps etc.

Overnight last night we have used 394 litres of water. Again, we did not use any showers, toilets, baths or taps during that time.

So with everything off we were still using lots of water for some reason.

So the only thing left that I could think of was the underfloor heating and water heating that is in our laundry cupboard.

So I switched off all the underfloor heating controllers in each room and ensured the manifold actuators were all closed. I then also switched the hot water controller to off instead of it using the timer schedules.

I took a new meter reading and waited an hour and to my suprise we had now only used 3 litres of water. I left it another hour and took another reading and that time we had used 1 litre of water. However, we did not use any taps or any water during that time so even with the heating and hot water off we still have some form of water leak/usage somewhere.

My first concern is why the underfloor heating and/or water heating is using such large amounts of water. Is it normal for underfloor heating to use so much water when it is on?

The underfloor heating and hot water are fed from an air source heat pump.

The hot water is held in a 200 litre cylinder next to the underfloor heating manifolds. We do not have any water tank in the loft.

I'm now going to test the modern dual flush toilets to see if they are using water when they shouldn't be. They appear to be dry around the pan and I can't isolate them easily because the shutoff valves for each toilet has been boxed in.

Unfortunately our landlord did not provide us with any instructions for this heating system in this house so I'm having to learn it as I go along.

Thanks,

Chris

 

[John.g]

The heating systems shouldn't use a drop of water, maybe the occasional top up of a few litres every couple of months, it points to a leak on the mains between the stopcock and the house but you could repeat the heating test again say one hour off then repeat with one hour back on, no domestic use for these two hours.

 

[ShaunCorbs]

Any toilets running / overflowing ?

A bit of food dye in the cisterns will tell you if there passing / overflowing

 

[John.g]

"The hot water is held in a 200 litre cylinder next to the underfloor heating manifolds. We do not have any water tank in the loft."
You may have a unvented HW cylinder except that you have a combined HW cylinder and storage tank, if unvented you will have a PRV (pressure relief valve) on the cylinder and probably another one called a expansion valve after the cold water pressure reducing valve to the HW cylinder, both of these will vent into a tundish so ensure especially at night that neither is expelling water, this can happen if you have very high mains pressure and the pressure reducing valve is faulty.

 

[JX350C]

Hi all,

Thank you for all the helpful replies. They are much appreciated.

I unfortunately cannot isolate the toilets because the isolation valves are boxed in behind each toilet. So I was unable to find a way to test them by themselves to see if they are using the 3 or 4 litres per hour that we are losing when the DHW and underfloor heating are off. I can't see any water running down the back of the pan and they both seem to stay dry for both toilets.

So last night I switched on the hot water again to try to work out if the high water usage is being used by the DHW or the underfloor heating or both. I left the underfloor heating off. The DHW was just switched on as auto at the control panel and is only scheduled to come on once at night.

I then took a meter reading this morning and we had used 580 litres of water overnight.

We only used the toilet a few times and we didn't use any baths or showers. We didn't even put the dishwasher or washing machine on.

I have once again switched off the main stopcock in the house and the meter in the street then does not change. I have tested that over several hours and the reading never changes. So there is definitely something in the house using all this water. At the moment the main culprit appears to be the DHW or underfloor heating.

Thanks,

Chris

 

[ShaunCorbs]

Is your heating system sealed eg do you top it up with a filling loop ?

 

[John.g]

When you think of it 580L loss over say 8 hours is "only" 1.2LPM.
If its the UFH then check that the topup system has a auto fill PRV, if so, shut it. If HW and not on the hot side check the cold water inlet tundishes.

 

[EvilDrPorkChop]

When you think of it 580L loss over say 8 hours is "only" 1.2LPM.
If its the UFH then check that the topup system has a auto fill PRV, if so, shut it. If HW and not on the hot side check the cold water inlet tundishes.

If something was leaking at 1.2lpm that would show itself pretty quick - unless of course it's going down a drain

 

[JX350C]

Is your heating system sealed eg do you top it up with a filling loop ?

Unfortunately I don't know enough about this system yet as we were not given any instructions when we moved in so I'm trying to learn as I go along. I'm also just a DIYer.

 

[ShaunCorbs]

Ok do you have a cylinder or just a boiler ?

 

[JX350C]

When you think of it 580L loss over say 8 hours is "only" 1.2LPM.
If its the UFH then check that the topup system has a auto fill PRV, if so, shut it. If HW and not on the hot side check the cold water inlet tundishes.

Thank you. I will try to locate those once I work out what they look like. I will upload some pictures of the install once I have them off the phone. The tank is a Grant HPFR200PPC/BS Monowave Unvented Single Coil Indirect Cylinder with 50 Litre buffer.

 

[JX350C]

If something was leaking at 1.2lpm that would show itself pretty quick - unless of course it's going down a drain

I do see that there is pipework from the cylinder that appears to go into drain plumbing. Near the start of that pipe is what I now know is a tundish. I've learnt something new today. About half way along that pipework is a T join that appears to go into a pressure meter which is in turn connected to the bottom of a large red cylinder. Looking at the tundish there are no drips or running water through it and it is completely dry.

 

[ShaunCorbs]

So sealed system so won’t be heating

Any pictures of the toilets ?

 

[JX350C]

Ok do you have a cylinder or just a boiler ?

I don't have a boiler because we have an air source heat pump that heats the water. The cylinder is a Grant HPFR200PPC/BS Monowave Unvented Single Coil Indirect Cylinder with 50 Litre buffer.

 

[Murdoch]

What does your landlord say about the situation?

 

[JX350C]

What does your landlord say about the situation?

I have actually just spoken to my landlord, who is very supportive, and I've just spoken to his plumber who originally installed the system and he is coming over next week to investigate.

In the meantime I've just got some food colouring so I can take the top off the toilets and test if they are using any water when they shouldn't be.

 

[JX350C]

So the plumber came over today to investigate. All he did was open the manhole outside to see if there was water running and he checked the stopcock in the house was open. There was no water running down the drain outside. He then wanted to see if the meter changed when water was being used. I put a tap on in the house and the meter was changing. He didn't test anything else and instead suggests that the water company come out and test the meter etc. He says that he thinks the meter does not record litres used in the red portion of the meter reading. He said the black portions of the meter are litres. I have been told by the water company that the numbers in the black portion are cubic metres (1000 litres) and that the red portion are litres. I showed him my meter reading records and he seems to think that they are not litres and seems to think there is nothing to worry about. He didn't do any testing of anything in the house and didn't even look at the DHW or heating system. I feel foolish for getting the plumber over and maybe I have been given incorrect information from the water company on how to calculate the water usage. Maybe I have been given incorrect information from the water company but they are saying that we are using 5 times the usage of a normal household. I have just spoken to the water company and they are sending someone out to do some testing.

Does anyone know how to calculate the my actual usage, as I'm now not sure I am doing it correct? My meter has 8 digits on the reading. 5 are in the black and three are in the red to the right hand side of the reading.

Thanks,

Chris

 

[John.g]

Mine looks like what it says on the tin...... so that reading below is 1,234M3, 670litres, if you use say 580 litres then the reading becomes 01235250.

 

[JX350C]

Mine looks like what it says on the tin...... so that reading below is 1,234MS, 670litres, if you use say 580 litres then the reading becomes 01235250.

View attachment 82209

Thanks for that. That is exactly my understanding but the plumber seems to think that is not correct so left me feeling very confused and stupid and was insistent that I was wrong.

I simply subtract the previous meter reading from current reading to get the amount of litres used over that period.

Here is an example of my meter readings over the last week or so:

16/03/2023 09:09​	00478324​	394​
16/03/2023 12:54​	00478432​	108​
16/03/2023 14:03​	00478435​	3​
16/03/2023 15:00​	00478436​	1​
16/03/2023 15:49​	00478461​	25​
16/03/2023 17:32​	00478465​	4​
17/03/2023 10:32​	00479045​	580​
21/03/2023 15:18​	00481909​	2864​

The third column is the difference between the previous meter reading so, if my calculation is correct, should be the number of litres used between the readings. The meter readings with low numbers are when I had the DHW and underfloor heating switched off. So I am convinced this is being caused by either of those. But he didn't even check those and just said that it can't possibly be them.

Thanks,

Chris

 

[John.g]

All present and correct.

Did you try the consumption with the DHW switched off only and then the UFH switched off only.
The UFH should be the easiest to check out, locate the (red) expansion vesse (or vessels) then locate the filling loop, some filling loops have a flexible hose with shut off valves at both ends, ensure both of these shut off and slacken the hose off at both ends to ensure no water passing. Other systems have a auto fill system where a pressure reducing valve set to 1.0bar keeps the system pressed up, this also has a isolating valve before the pressure reducing valve, shut this.
DHW: There should be a isolating lever or gate valve on the cold mains suppy to the cylinder, shut this.

 

[JX350C]

Thanks John. At the moment I've just switched the underfloor heating off by switching off the controllers in each room and ensuring the actuators are closed. When the DHW is switched off I have only changed the mode on the control panel to off instead of in the auto position which manages the DHW on a schedule. I do have the red tank you mention and there is a large blue lever on the cold water mains to the cylinder. I'll try to do what you have suggested and I am now going to also take meter readings every hour, record exactly what we used and then see if the meter readings tally with the actual usage.

Thanks,

Chris

 

[EvilDrPorkChop]

Maybe some photos of the install would help?

 

[John.g]

Thanks John. At the moment I've just switched the underfloor heating off by switching off the controllers in each room and ensuring the actuators are closed. When the DHW is switched off I have only changed the mode on the control panel to off instead of in the auto position which manages the DHW on a schedule. I do have the red tank you mention and there is a large blue lever on the cold water mains to the cylinder. I'll try to do what you have suggested and I am now going to also take meter readings every hour, record exactly what we used and then see if the meter readings tally with the actual usage.

Thanks,

Chris

Re the UFH, You will have to ensure that the make up filling is isolated, it doesn't matter how many controllers or actuators are closed.

 

[JX350C]

Maybe some photos of the install would help?

I managed to get some photos which I will upload for you.

 

[JX350C]

Re the UFH, You will have to ensure that the make up filling is isolated, it doesn't matter how many controllers or actuators are closed.

Thanks John. Understood.

 

[JX350C]

 

[JX350C]

Those are the only photos I have so far. I need to move out our laundry shelving to get pictures of the UFH manifolds and controls and the other pipework. I will try to do that tomorrow and upload them.

Thanks,

Chris

 

[JX350C]

Here are some other photos of the red expansion tank that I have previously taken. I have noticed from these photos that the isolation valves connecting the flex pipe to the cold water feed are in the off position. Should they be in the open position during normal every day use? I haven't noticed this before.

 

[ShaunCorbs]

No you should only open them when you want to refill the heating system by the looks of it you need to

Open one first eg inline with the pipe

Then slowly open the last one until you hear water don’t open it any more watch the pressure guage when it gets just above one shut that valve then shut the other one

 

[JX350C]

No you should only open them when you want to refill the heating system by the looks of it you need to

Open one first eg inline with the pipe

Then slowly open the last one until you hear water don’t open it any more watch the pressure guage when it gets just above one shut that valve then shut the other one

Thanks ShaunCorbs. I will do that.

 

[John.g]

Its probably been months or even a year or so since the last top up so that rules out any part of the heating system as the culprit.

Just to return to the meter, it may be no harm to take a meter reading, then run off some cold water into a 10 or 20 litre drum and note the metered consumption.

 

[JX350C]

Its probably been months or even a year or so since the last top up so that rules out any part of the heating system as the culprit.

Just to return to the meter, it may be no harm to take a meter reading, then run off some cold water into a 10 or 20 litre drum and note the metered consumption.

Thanks John. That is a great idea. I will try that test later today. I am keeping an extended log today and recording meter readings every hour or so and keeping a log of what water we know we used during those times.

 

[plumbingservices]

This is absolutely insane! the underfloor heating controllers should not use this much water.

 

[JX350C]

This is absolutely insane! the underfloor heating controllers should not use this much water.

I agree. The amount of water we are using is insane and something is using water somewhere even when we seem to have things switched off. I've been logging every time we use water and what we used and then taking meter readings roughly every hour to see if the estimated usage matches the meter readings. At the moment I haven't been able to work out exactly what is causing this water usage. Tomorrow I am going to start isolating the DHW, Underfloor heating, showers, toilets (although those are boxed in so I cannot access their isolation valves) to see if I see a drop in usage.

 

[ShaunCorbs]

It’s not the ufh / heating as it’s sealed and won’t refill

 

[JX350C]

I've now managed to get some further testing done. I've shut off all isolation valves to all the taps, toilets, dishwasher, washing machine etc and I can see that the meter is still increasing without any visible water usage. I then isolated the showers and checked that the fill loop was closed to the UHF. Water was still being used. I then switched the hot water controller to off instead of auto and water was still being used.

So I then isolated the water supply to the laundry room where the cylinder, heating controls and UFH manifolds are. The water usage then stopped immediately. Below is the valve I switched off.

This valve supplies cold water to the showers, UFH fill and the cylinder. I have shut off the showers as they have smaller isolation valves after that main valve. I've confirmed that the fill for the UFH is closed and it is not letting water past at all. However, there is no further isolation valve to the cylinder so I can't seem to isolate that on it's own.

 

[John.g]

Ensure all hot taps off then shut that lever valve again and after a few minutes open any hot water tap, you should get a few litres (from the expansion tank) flowing.

 

[John.g]

Can you have a look at the photo.

 

[ShaunCorbs]

Can you have a look at the photo.

That’s a 3 bar safety valve

 

[JX350C]

Can you have a look at the photo.

That valve has the main cold water feed to it at the top and then two pipes from it. One of those out pipes goes down and connects to the cylinder and the other connects to the pipe with the tundish in it. I'll get a better picture of that for you.

 

[JX350C]

Can you have a look at the photo.

Here are some pictures of that valve and connections closer up. The pipe in the top of it is the main cold water feed which has the large blue isolation valve on it.

And the above image shows how it connects to the cylinder. This pipe by the way is quite hot but I presume that's because it's connected to the cylinder.

 

[John.g]

Yes, (as Shaun pointed out), its the expansion valve probably set to 6bar since the cylinder temperature and pressure relief valve is set to 90C/7bar.
Theres another pipe underneath this expansion valve going off to the right?, where is the expansion vessel connected into the system
Are you absolutely sure that there is no water flowing down through the tundish.

 

[JX350C]

Yes, (as Shaun pointed out), its the expansion valve probably set to 6bar since the cylinder temperature and pressure relief valve is set to 90C/7bar.
Theres another pipe underneath this expansion valve going off to the right?, where is the expansion vessel connected into the system
Are you absolutely sure that there is no water flowing down through the tundish.

That pipe off to the right goes to a large white tank. I've taken some other pictures of the whole install but here is one showing that large white tank. And I do keep checking the tundish and there doesn't appear to be anything dripping through it.

 

[John.g]

Thats fine, its to the expansion vessel.
The cold water to the cylinder shoud not be hot except maybe very close except its flowing back and out through the expansion valve and down through the tundish when the cylinder is heating up and if the expansion vessel has failed but should still only expel a few litres of water each time the cylinder is heating up.

 

[JX350C]

Thats fine, its to the expansion vessel.
The cold water to the cylinder shoud not be hot except maybe very close except its flowing back and out through the expansion valve and down through the tundish when the cylinder is heating up and if the expansion vessel has failed but should still only expel a few litres of water each time the cylinder is heating up.

Ok thanks. That pipe is hot most of the way up until it gets near the T and then it's cooler above and to that white tank.

 

[ShaunCorbs]

If you turn the silver screwdriver valve off does the water meter stop ?

 

[JX350C]

If you turn the silver screwdriver valve off does the water meter stop ?

Sorry, which one do you mean?

 

[ShaunCorbs]

Sorry, which one do you mean?

The one by the white vessel 15mm silver valve on the hot

 

[JX350C]

The one by the white vessel 15mm silver valve on the hot

Ah ok. That one is to the feed for the showers. I'll try it. Thanks

 

[John.g]

Can you just switch off the laundry supply to get the meter to stop turning and then check the meter readings while filling a 10 or 20L bucket to confirm that it's metering correctly.

 

[JX350C]

We went out all day yesterday and took a meter reading in the morning and the meter read an increase of 569 litres since the previous day overnight. We didn't use any showers, baths or washing machine. We put on the dishwasher once in that period and used the toilets.

So yesterday after that meter reading, I switched off the mains water isolation valve in the laundry room. When we got home last night I took another reading and switched that valve back on. Over 8 hours the meter did not change so we did not use any water over that period with that valve shut off.

With that valve turned off, I ran a hot tap and within about 10 seconds the hot water stopped coming out of the tap.

My landlord is still convinced this problem is a faulty meter even though I have explained the problem and what I have found so far through my testing. He is going to send out another plumber but states that because he can't see any water running down the drain or outside the property then the problem must be the meter.

 

[ShaunCorbs]

Ask them to pressure test the hot water side

 

[JX350C]

Ask them to pressure test the hot water side

Will do, thanks for the help.

 

[John.g]

Have another look at post #50.

 

[JX350C]

Have another look at post #50.

Sorry, for some reason I missed your post. I'll take a look at doing that tomorrow. Thanks

 

[PETE 123]

Check if water is comiong out of condense pipe on boiler it this idea applies
as a heat exchanger may be leaking.

 

[JX350C]

The second plumber came over this afternoon and was really helpful and listened to what the problem was. He went over the basics with me that I had already checked and with everything switched off, and not using any water, apart from the stopcock or the laundry room we checked the meter and it was constantly increasing. He could then see the same problem that we have been seeing.

He thoroughly tested everything and checked around and under the house for water leaks. He found no leaks. Whilst pressure testing he found that the water pressure increased slightly when he isolated the water feed to one of our showers. He found that if he turned the temperature control fully off to 0 on the shower with the shower actually off, the water pressure would increase. Together we checked the meter and it stopped turning when the temperature control on the shower was turned fully to 0 and with the shower off. We retested by turning the control above the 0 position and it immediately started increasing the meter reading. So it looks like the constant 3 to 4 litres of water usage per hour is because of this faulty shower control which appears to be using water even when it is off. We can't determine exactly where the water is going because it's not coming out of the shower head or leaking from the mixer or the controls on each end of the mixer.

Whilst he was testing he said that he noticed the mains water pressure was at 4.5 bar with the shower temperature control problem but when he shut off the shower feed the pressure increased and fluctuated between 6 and 6.5 bar. He showed me a pressure gauge that is on the main water feed after stopcock so I can keep an eye on the pressure. I didn't even notice there was one fitted. There is also a PRV fitted between the stopcock and the pressure gauge and he said that was fully open so he thinks we are losing a lot of water at night as the pressure to the house is increasing overnight and the pressure is being relieved from the cylinder by water going down the overflow pipe through the tundish and hence we are not seeing any water loss through the tundish through the day. He said the cylinder is set to 6 bar before it will relieve the pressure so we think the pressure to the house at night is going much higher. So he has altered the PRV so that the pressure is lowered to 3.5 bar and all the taps in the house can be used at the same time with minimal changes to the flow of each tap. One thing I did notice when testing was that there were signs of water staining on the wooden flooring under the tundish pipe. I hadn't noticed before, but that clearly shows water has been running through the tundish at some point.

We have left the shower temperature control set to 0 for now and there has still not been any water usage for a few hours now. We will not use that shower and I am going to keep taking meter readings for the next two or three days to see if there are any spikes of usage when we know we are not using water and also overnight when we were seeing the huge amounts of water loss. That will hopefully confirm if this is fixed or not.

This is the shower controls that are at fault. The right hand control is the one using water even though the shower is off.

 

[John.g]

There is a PRV on the combination set right at the HW cylinder, did he check this, it would/should have been set to 3.0 bar, if this too is fully open then it would be surprising that you didn't observe water flowing down the tundish even during the day.

Possible though that even with the cold mains to the cylinder PRV set to 3.0bar that the cold water at 6bar is getting through the shower mixer and pressurizing the cylinder via the hot shower supply, then down the tundish, time will tell.

 

[PETE 123]

Could it be that the hot on shower is mains and is passing to the cold that is on a tank supply.

 

[JX350C]

There is a PRV on the combination set right at the HW cylinder, did he check this, it would/should have been set to 3.0 bar, if this too is fully open then it would be surprising that you didn't observe water flowing down the tundish even during the day.

Possible though that even with the cold mains to the cylinder PRV set to 3.0bar that the cold water at 6bar is getting through the shower mixer and pressurizing the cylinder via the hot shower supply, then down the tundish, time will tell.

Thanks John. I'm not sure if he tested the PRV on the right of the HW cylinder. I left him for some of his testing but I know he spent a considerable amount of time testing valves, taps, showers etc.

Exactly, time will tell. I'm keeping logs for the next few days to see. During the day I didn't see any water running down through the tundish and I was regularly checking it. I'll keep you all updated.

 

[John.g]

My kingdom for a pressure gauge on the HW cylinder, it would save a lot of hassle and expense for people if it was included as standard on all unvented HW Cylinders.
Your findings are very interesting in that your plumber saw the pressure rising/falling by 1.5 to 2.0 bar to 4.5bar, if, which seems the more likely explanation at the moment, it is flowinng back through the shower & HW cylinder expansion valve then down the tundish then it points to either the E.valve (or the cylinder safety valve) are gone weak and lifting at 4.5bar or the E.valve has been set too low, also if the HW cylinder PRV has been set to 2.8 to 3.0bar then the E.valve could lift each time a big volume of water is reheated, admittedly to only discharge ~ 4 or 5 litres each time. Also loosing say 400L at night through the HW cylinder should mean that the whole cylinder had to be reheated each morning from practically stone cold, did you notice anything strange about the heat up times?

 

[JX350C]

My kingdom for a pressure gauge on the HW cylinder, it would save a lot of hassle and expense for people if it was included as standard on all unvented HW Cylinders.
Your findings are very interesting in that your plumber saw the pressure rising/falling by 1.5 to 2.0 bar to 4.5bar, if, which seems the more likely explanation at the moment, it is flowinng back through the shower & HW cylinder expansion valve then down the tundish then it points to either the E.valve (or the cylinder safety valve) are gone weak and lifting at 4.5bar or the E.valve has been set too low, also if the HW cylinder PRV has been set to 2.8 to 3.0bar then the E.valve could lift each time a big volume of water is reheated, admittedly to only discharge ~ 4 or 5 litres each time. Also loosing say 400L at night through the HW cylinder should mean that the whole cylinder had to be reheated each morning from practically stone cold, did you notice anything strange about the heat up times?

No I hadn't noticed anything about the heat up times. This is the first time we have had this system and the first we knew about a problem was when the water company commented that we are using very large amounts of water.

 

[EvilDrPorkChop]

Well really all the showers etc. mixer taps should of been taken off the Balance cold on the Combination Valve on the cylinder to prevent this. The easiest way to sort this would be either fit a PRV on the incoming main to 3 bar, or fit a Non return valve to the Hot Outlet on the cylinder.

 

[Chuck]

No I hadn't noticed anything about the heat up times. This is the first time we have had this system and the first we knew about a problem was when the water company commented that we are using very large amounts of water.

There's one thing worse than throwing large amounts of water down the drain and that's... throwing large amounts of hot water down the drain! 🙂 I suggest you read your meter(s) now so you can compare consumption of gas before and after fixing the problem.

Now you've found a decent plumber, make sure he gives the system a thorough checking-over. I'd try to get a written note of his name, company, and findings so if you want to reclaim the cost of the wasted water and/or gas from the landlord you have the evidence needed to do so.

 

[John.g]

Well really all the showers etc. mixer taps should of been taken off the Balance cold on the Combination Valve on the cylinder to prevent this. The easiest way to sort this would be either fit a PRV on the incoming main to 3 bar, or fit a Non return valve to the Hot Outlet on the cylinder.

Apparently there is a PRV installed on the mains after the stopcock with a PG after it, the plumber found the PRV full open with a apparent mains pressure of 6.0/6.5bar but its a bit strange that this faulty shower was causing the pressure to fall to 4.5bar with it fully open, he has now reduced the PRV pressure to 3.5bar, if this pressure falls excessively with water usage then possibe PRV fault or stopcock or mains restriction that was the reason for the PRV wide opening in the first place and the installation of a pressure gauge?.

 

[John.g]

No I hadn't noticed anything about the heat up times. This is the first time we have had this system and the first we knew about a problem was when the water company commented that we are using very large amounts of water.

Is the water consumption normal now?

 

[JX350C]

Apologies for the radio silence for a while. I've been busy at work and had to work all weekend.

I've been busy taking meter readings most days and especially keeping an eye on overnight readings when we were losing the largest volumes of water. I wanted to ensure that the readings actually reflect our usage so I have been logging each use and then comparing them to the meter reading usage. So far the usage matches the meter readings so this does look like this problem is now fixed. I am continuing to take readings just to ensure they are all good. If all is now good the landlord said he will get the shower fixed as well. He has at least now listened to the evidence and the plumbers findings so has agreed that the problem is not the meter at fault.

Thanks for all the help with getting to the bottom of this. It was very frustrating trying to prove the usage was not from our use but the last plumber was great and saw for himself the constant water usage. It was such a relief when he found the cause of the problems.

Question now is, who should pay me back for all the water that was used that was not our fault.

 

[Chuck]

Question now is, who should pay me back for all the water that was used that was not our fault.

Consult your household insurance, but I'm pretty sure my policy wouldn't cover your scenario. I think that the landlord is the only person you have a claim against. (They, in turn, might be able to pursue the builder of the house.) Seek advice from a solicitor or Citizen's advice before making a claim.

Your landlord will probably assert that they are only responsible for the losses that occurred after you notified them of the problem, which is a position I have some sympathy for but which may or may not be how the law would see it.

It may be worth seeing if the water supplier will give you a rebate. I think this would be discretionary on their part but given the efforts you had to go to identify and fix the leak they might play ball.

Citizens Advice is a charitable organisation. If you consult them and can afford to make a donation, please do so.

 

[Old UKPF 106228]

I would ask the water company to consider a lost water allowance

You could thank the water company for bringing the high water usage to your attention. Explain what has been done to resolve the problem. It might help to inform the water company that you are a tenant.

Good luck.

 

[John.g]

This was a new build so possibly not installed correctly as the cold water supply to the HW cylinder was/is not from the balanced cold connection on the combination valve set, and the HW expansion valve may not have been set correctly to 6.0 bar or it was reduced to 3.5/4.0 bar, it certainly looks as if it wasn't commissioned properly, if at all, the mains PRV was fully opened with the stopcock left throttled in.

 

[JX350C]

This was a new build so possibly not installed correctly as the cold water supply to the HW cylinder was/is not from the balanced cold connection on the combination valve set, and the HW expansion valve may not have been set correctly to 6.0 bar or it was reduced to 3.5/4.0 bar, it certainly looks as if it wasn't commissioned properly, if at all, the mains PRV was fully opened with the stopcock left throttled in.

Yes I totally agree. I'm convinced this has been a problem since we moved in. We have written to the water company to see what they say.