Clattering noises from the hot water system
- Thread starter UKnewbie
- Start date
The heating guys with more experience may know where to go to straight away.
If it was me I would look at the Flow pipe from the boiler for a start. If a condensing boiler it might be round about 60C; if an old iron one it might be as hot as 80C, but in either case the boiler control knob should increase or decrease it, so I don't know why yours is overheating, I'd be looking at the working of the thermostat.
If the Load on the circuit is correctly regulated, the return should be in the region of 10-20C lower.
A modern boiler can modulate its power according to demand, and might run at small flame size when just heating the cylinder. An old iron boiler is 100% on or 100% off, which would provide more heat than the cylinder can absorb, so the boiler would go and off.
This site does not permit advice on dismantling or repairing parts which may impact gas safety, so I'm just looking at understanding the problem.
If it was me I would look at the Flow pipe from the boiler for a start. If a condensing boiler it might be round about 60C; if an old iron one it might be as hot as 80C, but in either case the boiler control knob should increase or decrease it, so I don't know why yours is overheating, I'd be looking at the working of the thermostat.
If the Load on the circuit is correctly regulated, the return should be in the region of 10-20C lower.
A modern boiler can modulate its power according to demand, and might run at small flame size when just heating the cylinder. An old iron boiler is 100% on or 100% off, which would provide more heat than the cylinder can absorb, so the boiler would go and off.
This site does not permit advice on dismantling or repairing parts which may impact gas safety, so I'm just looking at understanding the problem.
If you do this, be sure to paint, ink or stick on some BLACK sticky tape - Matt if you can. The emmisivity of copper means that it doesn't emit the correct "equivalent" of a black body at the same temperature - you get wilidly different temperauture readings. There is a conversion for it.. but sticking on black tape is easier!
Nozzle
Thanks Nozzle! So some satin finish insulation tape or matt black paint.
Thanks John, yes, the return of the cylinder was a lot hotter than I would've expected (esp. that I drew down the cylinder and it had cool water in it).
I know feeling the rads there is quite a difference - it's usually supposed to be 12c I believe. On the cylinder I couldn't touch either pipe for more than a second or two.
When you say the load on the circuit being regulated, do you mean throttling/adjusting the flow of the return pipe? I have a valve on the return that is fully open. Is that OK?
Thanks John, yes, the return of the cylinder was a lot hotter than I would've expected (esp. that I drew down the cylinder and it had cool water in it).
I know feeling the rads there is quite a difference - it's usually supposed to be 12c I believe. On the cylinder I couldn't touch either pipe for more than a second or two.
When you say the load on the circuit being regulated, do you mean throttling/adjusting the flow of the return pipe? I have a valve on the return that is fully open. Is that OK?
the valve you mention is used to balance when the boiler is simultaneously heating both the cylinder and the radiators. To prevent all the hot water from the boiler lazily circulating through the cylinder and ignoring the radiators.
if the valve is trying to heat them both at the same time (some systems give priority to HW) you may notice the radiators lose heat and the house cools down after you've run a bath.
On a cold night, my house used to do that before I got CWI. I now have a more powerful boiler so it could cope anyway.
On a cold night, my house used to do that before I got CWI. I now have a more powerful boiler so it could cope anyway.
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