Please can anyone answer 3 questions about central heating?

[Martell]

I'd be so grateful!
1) If the water in the rads and pipes is so hot that I can't touch the rads, is it possible that I can hear it rushing and coursing through the rads and pipes? I've been told the noise is air in the system, but I'm wondering if it's boiling hot water instead.
2) When bleeding/venting rads, no air is coming out but sometimes the water spurts out (rather than trickling). When it spurts out, is that because there's air coming out too with the water?
3) Is it normal for my rads to go stone cold and the whole house become freezing and for it to take over an hour before the room thermostat tells the boiler to come back on to heat the house? I'm boiling hot and then freezing cold all evening!

 

[jitenbulsara]

The room stat will send signal to boiler based on the temperature where it is located.If the stat is sending signal to the boiler and the boiler is not reacting and you say it takes up to an hour to come back on then I would say there is an issue.

Is it a combi boiler or concenventional system?..

 

[Riley]

You said on your peevious thread you were going to get an engineer out. Did you??

 

[Martell]

You said on your peevious thread you were going to get an engineer out. Did you??

Thank you!! I feel I need to understand what might be going on. I've had problems for a couple of months since an engineer drained the system and refilled it and then refused to come back to even look at the problem. I then had another engineer who advised me to keep bleeding the rads (air in system). I've bled the rads twice a day for 2 weeks. I'm getting no air out (unless air comes out with the water that spurts out) but the rushing coursing noise continues in the rads and pipes. I feel I need to have a basic understanding of what might be going on before I call out an engineer again, which is likely.

 

[jitenbulsara]

Combi or conventional hearing system??...

 

[SimonG]

Stop bleeding the system when it's running and turn the boiler thermostat down.

can't understand why the first engineer wouldn't return!

 

[Martell]

The room stat will send signal to boiler based on the temperature where it is located.If the stat is sending signal to the boiler and the boiler is not reacting and you say it takes up to an hour to come back on then I would say there is an issue.

Is it a combi boiler or concenventional system?..

Thank you. It's a combi system. I don't think the room stat is sending a signal. The room stat allows the temperature to drop by half a degree (it uses increments of half a degree) before it tells the boiler to come back on. Amazingly, in the time it takes the room stat to register that the temp has dropped by only half a degree, the house is freezing (the rads are stone cold). This can take over an hour (without heating so no wonder the house is cold). I wonder if the room stat just isn't registering the temperature drop quickly enough (it's just taking its time to drop) or if it should send the signal to the boiler much sooner. As you say, it doesn't seem right.

 

[dancinplumba]

Thank you. It's a combi system. I don't think the room stat is sending a signal. The room stat allows the temperature to drop by half a degree (it uses increments of half a degree) before it tells the boiler to come back on. Amazingly, in the time it takes the room stat to register that the temp has dropped by only half a degree, the house is freezing (the rads are stone cold). This can take over an hour (without heating so no wonder the house is cold). I wonder if the room stat just isn't registering the temperature drop quickly enough (it's just taking its time to drop) or if it should send the signal to the boiler much sooner. As you say, it doesn't seem right.

do you have TRV's on radiators where room stat is ? are your radiators sized correctly ?

 

[Martell]

Stop bleeding the system when it's running and turn the boiler thermostat down.

can't understand why the first engineer wouldn't return!

Not bleeding the system when it's running! Turned the boiler thermostat down and it helped (which led me to wonder if in fact the rushing noise was being caused by boiling hot water, not air). First engineer not interested in the problem he caused, promised to contact me but didn't bother - it happens!!

 

[Riley]

I would say take a video of this sound but we will obviously never get a true representation of it. I would be very surprised if the water was boiling as your boiler and system would be bouncing off the wall from memory I believe you said you had some TRVs changed I think you have to start there

 

[Riley]

Also I wasn’t being funny with my first post. I was wondering if you had an update

 

[Martell]

do you have TRV's on radiators where room stat is ? are your radiators sized correctly ?

do you have TRV's on radiators where room stat is ? are your radiators sized correctly ?

Interesting you should ask - I do have TRVs on the rads where the room stat is, but I didn't until the first engineer drained and refilled the system and fitted them. However, the 2nd engineer wasn't concerned about them. I believe the rads are sized correctly.

 

[Riley]

Shouldn’t have TRVs in the same room as the stat as they will constantly fight against each other

 

[Martell]

I would say take a video of this sound but we will obviously never get a true representation of it. I would be very surprised if the water was boiling as your boiler and system would be bouncing off the wall from memory I believe you said you had some TRVs changed I think you have to start there

Thanks. I recorded the noise on my phone and it wasn't representative of the noise. The replies on this forum keep coming back to the TRVs, as you said. The original engineer fitted TRVs where there hadn't been TRVs.

 

[Martell]

Shouldn’t have TRVs in the same room as the stat as they will constantly fight against each other

Thanks again. That's the message I'm getting on this forum. If I was handy, I'd remove the TRVs (I know it's not that difficult to do, but I couldn't do it). I'll ask an engineer. Interesting that you say the noise isn't likely to be caused by the high temperature of the water. Appears I can discount that as a cause and go back to concentrating on air in the system and/or the TRVs.

 

[Riley]

And as was said in your original thread the stat shouldn’t be in the same room as TRVs

 

[Riley]

Is the stat wireless

 

[Martell]

Combi or conventional hearing system??.

Combi (Worcester boiler 3 yrs old)

 

[Martell]

Is the stat wireless

Yes it's wireless and not located near rads

 

[Riley]

I believe you said that the stat was originally in the hall with no problems. I’d be tempted to put it back

 

[dancinplumba]

Thanks again. That's the message I'm getting on this forum. If I was handy, I'd remove the TRVs (I know it's not that difficult to do, but I couldn't do it). I'll ask an engineer. Interesting that you say the noise isn't likely to be caused by the high temperature of the water. Appears I can discount that as a cause and go back to concentrating on air in the system and/or the TRVs.

take the head off the TRV's !!!

 

[Riley]

There have been several good ideas over three threads which have not been tried

 

[Harvest Fields]

Thank you. It's a combi system. I don't think the room stat is sending a signal. The room stat allows the temperature to drop by half a degree (it uses increments of half a degree) before it tells the boiler to come back on. Amazingly, in the time it takes the room stat to register that the temp has dropped by only half a degree, the house is freezing (the rads are stone cold). This can take over an hour (without heating so no wonder the house is cold). I wonder if the room stat just isn't registering the temperature drop quickly enough (it's just taking its time to drop) or if it should send the signal to the boiler much sooner. As you say, it doesn't seem right.

Where is the room thermostat stat located? And how far away is it from the nearest radiator?

 

[Harvest Fields]

Thanks again. That's the message I'm getting on this forum. If I was handy, I'd remove the TRVs (I know it's not that difficult to do, but I couldn't do it). I'll ask an engineer. Interesting that you say the noise isn't likely to be caused by the high temperature of the water. Appears I can discount that as a cause and go back to concentrating on air in the system and/or the TRVs.

Send a picture of the trvs and we will tell you how to unscrew the head from it on a temp
Basis.

 

[Martell]

Where is the room thermostat stat located? And how far away is it from the nearest radiator?

Thank you. The room stat is about 10 feet away from the nearest rad and about 7 feet off the floor. It's set 5 degrees higher than the actual room temperature.

 

[Riley]

Why won’t you remove the trv heads or move the stat

 

[Martell]

Send a picture of the trvs and we will tell you how to unscrew the head from it on a temp
Basis.

Thank you. Attached photo! I'm a female pensioner! If you tell me what to do, I'll be grateful but I might need help!

 

[Harvest Fields]

The bit that I have circled in the picture needs to be undone and then the head will come off the trv. They may only be finger tight but if you struggle to grip things you may needs some adjustable grips.

 

[Martell]

Why won’t you remove the trv heads or move the stat

I asked the engineer if the TRVs were causing the problem and he said they were ok. I'm going to try to remove the heads (I'm a female pensioner which is why I'm trying not to meddle too much myself but would rather get an engineer in to sort out the problem!). I have difficulty unscrewing parts that are tight. I tried to room stat in the hall and I didn't notice a difference, but I'll try relocating it again.

 

[Riley]

Sorry I wasn’t having a go but it had been said several times

 

[Martell]

The bit that I have circled in the picture needs to be undone and then the head will come off the trv. They may only be finger tight but if you struggle to grip things you may needs some adjustable grips.

View attachment 35462

Ok thank you very much. I'll try that tomorrow.

 

[dancinplumba]

Thank you. The room stat is about 10 feet away from the nearest rad and about 7 feet off the floor. It's set 5 degrees higher than the actual room temperature.

should be 4 ft

 

[Martell]

Sorry I wasn’t having a go but it had been said several times

No I know you're trying to help, but I've put all these suggestions to an engineer. He said draining and refilling the system wouldn't help, that he had no concern about the new TRVs that had been fitted, that I would need to keep bleeding the system as the noise was being caused by air, that the location of my room stat is not an issue. I do have faith in what he told me and he's offered to come back but it's taking too muc to solve the problem of the gushing sound in the pipes and rads but I wondered if I should be better informed or I'll just keep going over the same suggestions!

 

[Martell]

should be 4 ft

Ok thank you.

 

[Harvest Fields]

No I know you're trying to help, but I've put all these suggestions to an engineer. He said draining and refilling the system wouldn't help, that he had no concern about the new TRVs that had been fitted, that I would need to keep bleeding the system as the noise was being caused by air, that the location of my room stat is not an issue. I do have faith in what he told me and he's offered to come back but it's taking too muc to solve the problem of the gushing sound in the pipes and rads but I wondered if I should be better informed or I'll just keep going over the same suggestions!

The valves on the other end of the radiator may be restricted down to much. That causes noise.

 

[SimonG]

Open the trv head fully before you try and unscrew it. It can make it easier to remove.

 

[Martell]

The valves on the other end of the radiator may be restricted down to much. That causes noise.

Ok that's interesting. Would it be a gushing, coursing noise as if water is being forced through the rads and pipes? It's much worse if the boiler pressure is up to maximum. I've turned down the boiler pressure and eliminated the noise from the rads in my living room (still noisy in the hall and bathroom but they don't bother me). Trouble is, with the boiler pressure turned down, of course, the rads don't get so hot (ok for now but might not be ok when winter sets in).

 

[Martell]

Open the trv head fully before you try and unscrew it. It can make it easier to remove.

Cheers. Thanks very much.

 

[Riley]

Ok that's interesting. Would it be a gushing, coursing noise as if water is being forced through the rads and pipes? It's much worse if the boiler pressure is up to maximum. I've turned down the boiler pressure and eliminated the noise from the rads in my living room (still noisy in the hall and bathroom but they don't bother me). Trouble is, with the boiler pressure turned down, of course, the rads don't get so hot (ok for now but might not be ok when winter sets in).

How are you changing pressure??

 

[Martell]

How are you changing pressure??

Sorry perhaps I'm using the wrong words! The boiler has 2 dials with numbers, one for heating and one for hot water and the heating dial has been running at number 7 (maximum) so I turned it down to 5. I'm guessing this isn't pressure, then? It's temperature?

 

[Riley]

Ahhhhh I see with you now

 

[Martell]

Ahhhhh I see with you now

I guess it's the temperature I've reduced! I don't know why I thought it was pressure (cos ages ago I turned down the water temperature on the dial as the water in my taps was scalding so I should have realised it's a temperature gauge, not a pressure gauge!!)

 

[Riley]

I think realistically you need to try three things:
Remove trv heads
Open lockshields further
Move the stat

 

[Martell]

I think realistically you need to try three things:
Remove trv heads
Open lockshields further
Move the stat

Ok thanks very much. I'll try these things tomorrow.

 

[Rob Foster]

Ok thanks very much. I'll try these things tomorrow.

10 out of 10 for doing it yourself
The advice on here is the best
Let us know how you get on
Rob Foster aka centralheatking

 

[Ric2013]

1) I am told on this forum that the water would have to be above 100°C for any steam to remain as steam. My own experience makes me wonder if this is not the case, and I think I read somewhere that H2O can remain as gas or liquid over a range of temperatures.

2) Hard to answer from that description.

3) It can be normal for the rads to go stone cold, but not for you to freeze. I would suggest the hysterisis on the thermstat is too high (normally not adjustable these days, so new stat required), that the stat is wired incorrectly, or the stat is incorrectly located for your needs.

One problem is that the same room at the same air temperature can feel either hot or cold depending on whether there is a hot surface (e.g. a radiator) in it. The thermostat works on air temperature, so is unable to know if the radiator is hot or cold, or how warm you feel.

I have often considered in dull moments that a pneumatic time switch that turns the heating on for 20 minutes whenever you press it (i.e. heating only comes on when you decide you need it) might be more effective at keeping the rooms a good temperature and saving energy than a thermostat, but conventional thinking goes against this!

 

[Ric2013]

To be frank, turning the TRV head to the highest setting would be nearly as good as taking the head off altogether, in most circumstances.

 

[Martell]

10 out of 10 for doing it yourself
The advice on here is the best
Let us know how you get on
Rob Foster aka centralheatking

That's lovely of you, thanks. I've moved the room stat to the hall and removed one of the TRV's on the rad closest to where I sit (and therefore the most annoying rad!). The other 2 TRV's in my lounge won't budge without a wrench, which I don't have. But anyway, I'll see how the system behaves this evening (it's a lovely day so I won't learn much til the temp drops later, I guess). I have a friend calling on Sat, bringing a wrench!! I honestly don't mind calling out an engineer, but we don't seem to be trying anything new and I don't want to waste his time, so that's why I'm trying things myself! Thanks for your support.

 

[Martell]

To be frank, turning the TRV head to the highest setting would be nearly as good as taking the head off altogether, in most circumstances.

Thank you. That might be why my engineer wasn't concerned about the TRV'S. They're always on the highest setting. Anyway, I've removed on TRV very easily and relocated the room stat to the hall. I can see how the system behaves later. Helpful also to know it's unlikely to be the noise of hot water I can hear in the rads and pipes, though.

 

[Martell]

1) I am told on this forum that the water would have to be above 100°C for any steam to remain as steam. My own experience makes me wonder if this is not the case, and I think I read somewhere that H2O can remain as gas or liquid over a range of temperatures.

2) Hard to answer from that description.

3) It can be normal for the rads to go stone cold, but not for you to freeze. I would suggest the hysterisis on the thermstat is too high (normally not adjustable these days, so new stat required), that the stat is wired incorrectly, or the stat is incorrectly located for your needs.

One problem is that the same room at the same air temperature can feel either hot or cold depending on whether there is a hot surface (e.g. a radiator) in it. The thermostat works on air temperature, so is unable to know if the radiator is hot or cold, or how warm you feel.

I have often considered in dull moments that a pneumatic time switch that turns the heating on for 20 minutes whenever you press it (i.e. heating only comes on when you decide you need it) might be more effective at keeping the rooms a good temperature and saving energy than a thermostat, but conventional thinking goes against this!

Genius idea! I get really cold and give in and turn up the temp on the room stat to make the boiler come back on. Then I have to turn it down again when the room starts to overheat! I try not to as it can't be right that I'm constantly meddling with the room stat! I've been wondering why it can't be on a timer instead - 20 mins on and 20 mins off, say, would keep the temperature constant.