Very high water consumption

[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.