Discuss Please can anyone answer 3 questions about central heating? in the Plumbing Jobs | The Job-board area at PlumbersForums.net
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).
Cheers. Thanks very much.
- Messages
- 10,855
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?
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!!)
Ok thanks very much. I'll try these things tomorrow.
Rob Foster
Esteemed
- Messages
- 2,083
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
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!
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!
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.
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.
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.
Thanks again everyone for your really helpful advice. Removing the TRV head from rad in lounge means it's quiet (no whooshing water noise). I'm still bleeding the rads but I don't think I'm getting out any air from them unless air is mixed with the water as it comes out of the bleed valve (no air on its own, but the water ffffizzzzes out). Incidentally the water smells metallic. The bathroom and hall rads continue to make a rushing water noise as does the vertical pipe in the hall bringing water from upstairs but this noise doesn't bother me (as long as it's not an indication of air in the system!)
I'm still experimenting with the room stat. It behaved better last night with the TRV off the rad. The hall is not a good place as it's much warmer than the lounge!
The biggest issue now is a drumming noise which was there when the engineer came two weeks ago but which was somewhat masked by the whooshing rad noises. It starts 8 minutes after the boiler fires up and goes off immediately the boiler goes off. I asked the engineer about it and he thought it was part of the air in the system problem and would be eliminated when I got the air out. It's a random, rapid, drumming sound, difficult to pinpoint but it appears to be in the centre of the house (I can't hear it in kitchen or bathroom) and above my head when I'm in the lounge. I feel it's louder if I increase the temperature dial on boiler and quieter (not much) if I decrease it. I've put my head right up against the boiler and I don't think I could hear it. I thought it might be the pipes under the bedroom floors carrying water to one particular rad in a bedroom so I switched off the rad but the noise continued. If this isn't caused by air still in the system I'll have to ask the engineer to come back as it's not loud, but it's really annoying. I'd be really grateful if anyone could tell me what's likely to be causing this. Again, this only started happening a couple of months ago when the system was drained, leaking valves were repaired, 2 new TRV'S were fitted and the system was refilled. Thanks very much again.
I'm still experimenting with the room stat. It behaved better last night with the TRV off the rad. The hall is not a good place as it's much warmer than the lounge!
The biggest issue now is a drumming noise which was there when the engineer came two weeks ago but which was somewhat masked by the whooshing rad noises. It starts 8 minutes after the boiler fires up and goes off immediately the boiler goes off. I asked the engineer about it and he thought it was part of the air in the system problem and would be eliminated when I got the air out. It's a random, rapid, drumming sound, difficult to pinpoint but it appears to be in the centre of the house (I can't hear it in kitchen or bathroom) and above my head when I'm in the lounge. I feel it's louder if I increase the temperature dial on boiler and quieter (not much) if I decrease it. I've put my head right up against the boiler and I don't think I could hear it. I thought it might be the pipes under the bedroom floors carrying water to one particular rad in a bedroom so I switched off the rad but the noise continued. If this isn't caused by air still in the system I'll have to ask the engineer to come back as it's not loud, but it's really annoying. I'd be really grateful if anyone could tell me what's likely to be causing this. Again, this only started happening a couple of months ago when the system was drained, leaking valves were repaired, 2 new TRV'S were fitted and the system was refilled. Thanks very much again.
- Messages
- 7,272
not sure about that if fitted vertical
The initial 'air in the system' diagnosis may have given people tunnel vision. It may have been the problem once but after your fine work bleeding the system I suspect it is time to consider other possibilities. I think it is very possible, even likely, that:
Your 'swooshing' noises are turbulence due to the system pump being on too high a setting.
The 'drumming' noise is most likely the noise of pipes rubbing againsts something, e.g. joists as they expand as they heat up.
There is probably a reason the pump is set high, e.g. the system is not correctly balanced and someone turned the pump up to avoid the hassle of rebalancing the system. Or, it may just be that someone replaced the radiator valves with TRVs and left the original constant-displacement rate pump in the system. If the noise goes away when all the TRVs are fully open then this hypothesis is supported. Replacing the pump with a newer constant-head or 'smart' pump may be what's needed.
It's difficult to decide between these possibilities remotely but an experienced heating engineer should be able to get to the bottom of the problem without too much difficulty. If your current guy is not interested/able to fix the problem ask friends and aquaintences for recommendations and find someone who is.
Your 'swooshing' noises are turbulence due to the system pump being on too high a setting.
The 'drumming' noise is most likely the noise of pipes rubbing againsts something, e.g. joists as they expand as they heat up.
There is probably a reason the pump is set high, e.g. the system is not correctly balanced and someone turned the pump up to avoid the hassle of rebalancing the system. Or, it may just be that someone replaced the radiator valves with TRVs and left the original constant-displacement rate pump in the system. If the noise goes away when all the TRVs are fully open then this hypothesis is supported. Replacing the pump with a newer constant-head or 'smart' pump may be what's needed.
It's difficult to decide between these possibilities remotely but an experienced heating engineer should be able to get to the bottom of the problem without too much difficulty. If your current guy is not interested/able to fix the problem ask friends and aquaintences for recommendations and find someone who is.
Thank you. It seems then that I can definitely rule out air in the system. I've run the system with all the TRV's fully open and the swooshing noise continues in 2 rads and vertical pipe(s) as it always has from memory. I'm very grateful for your suggestions and there is nothing I feel I could be doing as, of course, I don't have the necessary expertise. It's obvious that I need to call the engineer back. I feel better knowing that I'm not just wasting his time (it's not just air in the system, though I know there was some air til about 10 days ago!). I have 7 years guarantee on the boiler so must go with a Bosch/Worcester trained engineer and I'm happy to go with this guy (he fitted the boiler 3 years ago and services it annually). Having said that, the problems will have to be resolved - especially the drummimg noise - as it's absolutely intolerable. Thanks very much again. I really appreciate your help.
Hmm. If it's a Worcester boiler with a built-in pump they are supplied (AFAIK) with the pump speed set to maximum and instructions to the installer to reduce the setting to the minimum that achieves satisfactory circulation. I've known otherwise quite careful engineers overlook this adjustment and, as a result, leaving the customer with a system that works but has radiators that get hot (unnecessarily) rapidly and lot of hydraulic noise from the pipes.
When correctly set-up, the whole system should have virtually no hydraulic noise, except perhaps when the TRVs are just on the point of closing but you'll only hear that when the house is otherwise quiet.
Good luck.
Thanks again for your support. Difficult to be sure, but I wouldn't have said that my radiators get hot rapidly, especially when winter sets in. In the summer I had major building works done, the building firm noticed some radiator valves were leaking and they repaired them. It was only when I turned on the heating a couple of months ago that I realised I'd been left with problems! So I think that the boiler installation was all correct as were the first couple of services. Anyway, I'll ask him to come back and sort it out. Thanks again.
Reply to Please can anyone answer 3 questions about central heating? in the Plumbing Jobs | The Job-board area at PlumbersForums.net
Similar plumbing topics
Hi, Can anyone advise as to why the cold water to my bathroom keeps airlocking?
This originally happened about 12 months ago and has happened 3-4 times since.
It’s an upstairs bathroom, fed from a tank in the attic. The tank is about 8 Meters away and feeds a bath, sink and toilet. The tank...
Hello all,
I'm would like to extend an existing outside tap to another point in the garden. I'm about to pour a concrete patio and was hoping to run the water line underneath. There are existing drain (and who knows what) pipes running along the same wall so I'm nervous about digging too far...
Hello all,
I’m replacing a concrete paving slab patio in the back yard. The original patio used 50mm deep concrete slabs on hardcore & sand. I’m planning to pour a 100mm deep concrete patio on 100mm hardcore. In order to achieve the same final height to line up with the rest of the patio, I...
Creating content since 2001. Untold Media.
Newest Plumbing Threads
-
What constitutes a Commercial Appliance and thus a Commercial Kitchen?
- Started by FozzieBear
- Replies: 3
-
POTTERTON PROMAX 28 COMBI Boiler - Hot Water Issue
- Started by boiler101
- Replies: 4
-
Hole in copper pipe, solder under floor, T coupling & protection- Started by dreikher
- Replies: 0
-
-
-
-
-
-
-
-
-
Sewer pipe problems not sure about it- Started by sammie81116
- Replies: 3
-
-
-