Scalding hot water and radiators.

[Joebananas]

Hello there, I'm hoping to get some advice about my heating system. I have a Baxi Bermuda Back Boiler. Installed in the early 80's so pretty old but still going strong! We have always found that our hot water is very hot and the pipe in the airing cupboard coming from the tank is too hot to touch. There is a thermostat on the tank in the airing cupboard which we have turned down but nothing seems to have happened. I had a look at the boiler itself and have turned the thermostat on the boiler from max (which I think was no 5) down to number 3 in the middle as I noticed that radiator in my 16 month olds room was burning hot to the touch and pretty dangerous with a toddler running around. Just wondering if you think the problem is the thermostat on the tank? or the boiler or something else? How easy is it to get fixed and is it costly? I have boiler cover but only if it completely conks out I believe. Any help much appreciated!!
Thanks.

 

[Darren Jackson]

Hi it does sound like the cylinder stat is faulty if you turned it down and made no difference. An easy job for any self respecting plumber just an hrs call out n price of a new stat. And ask the engineer to fit a TRV to juniors radiator to stop it from buring little fingers.

 

[Masood]

Hi it does sound like the cylinder stat is faulty if you turned it down and made no difference. An easy job for any self respecting plumber just an hrs call out n price of a new stat. And ask the engineer to fit a TRV to juniors radiator to stop it from buring little fingers.

Sound advice on both counts. You could do a lot worse than posting in here:

[DLMURL="http://www.ukplumbersforums.co.uk/im-looking-plumber-gas-engineer/"]I'm looking for a Plumber or Gas Engineer[/DLMURL]

One of our lovely lads or lassies will sort you out..

 

[Last Plumber]

A TRV won't stop the rad becoming to hot. TRV's regulate room temp so if there's a problem with system water temp, fitting one will not solve your problem or prevent the young, elderly or infirm from burning themselves on the hot surface.
You need to get a GSR to check the calibration of your boiler stat. On your boiler, with stat at max, it should be 82 degrees centigrade plus or minus 3 degrees.

 

[Masood]

A TRV won't stop the rad becoming to hot. TRV's regulate room temp

Ummm you might want to think about that mate. TRVs regulate room temp by regulating flow through the rad. Restrict the flow, less system water passes through, and it spends longer in the rad, dissipating more heat. Surface temp drops.

 

[Last Plumber]

I get where you're coming from but I disagree.

Let's look at a scenario ! If only to demonstrate my point .

It's the dead of winter and the house is cold, around 14 degrees c , it's early morning and the heating has been off all night.

The heating comes on, the TRV's are all open fully. That radiator, until the room temp starts to pass 16 degrees will be on the full temp that the boiler stat is set to.

I follow what you mean, in that, the warmer the room the lower the surface temp of the rads.

However, just because you install a TRV, you are not necessarily going to prevent high surface temperatures and you shouldn't suggest to a customer that installing one will prevent their child from burning themselves.

Am I wrong in your opinion ?

 

[Chalked]

If the water and rads are too hot. It looks like the boiler stat has gone out of calibration.
Water could be on gravity, so no stat.
You will need a gas safe engineer to replace this.

 

[heliotrope]

I get where you're coming from but I disagree.

Let's look at a scenario ! If only to demonstrate my point .

It's the dead of winter and the house is cold, around 14 degrees c , it's early morning and the heating has been off all night.

The heating comes on, the TRV's are all open fully. That radiator, until the room temp starts to pass 16 degrees will be on the full temp that the boiler stat is set to.

I follow what you mean, in that, the warmer the room the lower the surface temp of the rads.

However, just because you install a TRV, you are not necessarily going to prevent high surface temperatures and you shouldn't suggest to a customer that installing one will prevent their child from burning themselves.

Am I wrong in your opinion ?

You are not wrong. It is a common misconception that a TRV provides a radiator with cooler water from the system.

 

[Last Plumber]

You are not wrong. It is a common misconception that a TRV provides a radiator with cooler water from the system.

Thanks for that.

 

[tamz]

If your rads are too hot turn the dial on the boiler down. The temp settings on an old baxi are
1 - 140ºF (60ºC)
5 - 180ºF (82ºC)

10ºF (approx 5.5ºC) between each number so setting 3 means you're boiler is putting out water at around 160F or 70C

I wouldn't worry too much how hot the rad is in the room. Weans aren't as stupid as you think and after they touch it a couple of times they learn to leave it alone. It won't do them any harm unless they sleep with their face on it.
Hot water on the other hand presents a real danger for obvious reasons. Get the cylinder stat looked at and consider fitting a tmv to the bath.

 

[Dotty]

As ever grandpappy comes in with the voice of reason. ...

 

[tamz]

Nothing worth watching on the telly tonight John i'm even thinking of having an early night

 

[Masood]

You are not wrong. It is a common misconception that a TRV provides a radiator with cooler water from the system.

I absolutely did not say that! It can't provide cooler water as there is no way of cooling it until it's in the rad...

 

[Masood]

I get where you're coming from but I disagree.

Let's look at a scenario ! If only to demonstrate my point .

It's the dead of winter and the house is cold, around 14 degrees c , it's early morning and the heating has been off all night.

The heating comes on, the TRV's are all open fully. That radiator, until the room temp starts to pass 16 degrees will be on the full temp that the boiler stat is set to.

I follow what you mean, in that, the warmer the room the lower the surface temp of the rads.

However, just because you install a TRV, you are not necessarily going to prevent high surface temperatures and you shouldn't suggest to a customer that installing one will prevent their child from burning themselves.

Am I wrong in your opinion ?

I don't think you're 100% wrong but a decent TRV will start to modulate almost immediately. Remember the boiler stat will also do the same - allow full power initially and then start modulating...

 

[Last Plumber]

I don't think you're 100% wrong but a decent TRV will start to modulate almost immediately. Remember the boiler stat will also do the same - allow full power initially and then start modulating...

Not modulating on this boiler masood. Simple on off stat. Will go straight to 82 deg if set on Max and then off. What's more, it will maintain that temperature.

Even modern good quality TRV can fail or if the room is cold it will be open fully until room warms.

This is starting to get off the track now but, in order to prevent high temp on rads, you need
Low surface temp rads. There are other methods of course but like I say, we're getting of the thread I think.

 

[Joebananas]

Thank you so much everyone for your input. I really appreciate it. This is a really helpful forum.I spoke to a boiler engineer last night (I felt really sorry for the chap - I went through our boiler cover which is with Homeserve, they offered my a slot today and he phoned last night and tried to sort the problem over the phone at 8pm. Get the feeling that Homeserve work their sub-contractors quite hard??) Anyway, he said to turn the boiler stat down to min and then leave it 24 hours. The water does seem marginally cooler this morn but really only a little bit. Is turning the stat down to min really going to solve the problem?? Sounds like it's just moving the problem around to me and that actually it needs fixing properly?? Any further advice greatly appreciated. Just to clarify, I turned the stat on the tank in the airing cupboard down to about 40 yesterday lunchtime and the stat on the boiler down to 3, then turned the boiler stat down to min at 8pm last night. The timer for heating the water comes on twice a day for 2 hours in the morn and 1 in the eve before kids bathtime (if that's helpful?)
Thank folks!

 

[Masood]

Not modulating on this boiler masood. Simple on off stat. Will go straight to 82 deg if set on Max and then off. What's more, it will maintain that temperature

I was talking general rather than specifically about this boiler, and boiler stats can also fail, sp that's not an ideal solution either

But yes, we're going off topic!