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