Boiler stat failure on older boiler on open vented systems, if no overheat stat would lead to the water boiling and pumping over into the header tank. My neighbour had this problem 2 weeks ago and had to get it sorted, but I was thinking... why would this happen? I too have an older boiler and was just curious. How would the temperature get 100 degress and boil, as the switched live to the boiler would surely be cut by the cylinder or room thermostat before that could happen?? Just a thought? If anyone can explain this to me I'd be grateful to them.
Boiler stat failure? how?
- Thread starter reneel
- Start date
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cylinder stat/room stat take the temp of the water in cylinder or room temperature not the water curculating the boiler.
yeah i know that, oh i see i get it now, the water in the pipes is a lot hotter than that in the pipe itself, which will get to about 80ish...?
I suppose if the boiler stat fails and sticks in the on position then the room/cylinder stat won't cut out in time before it boils/pumps over?
I suppose if the boiler stat fails and sticks in the on position then the room/cylinder stat won't cut out in time before it boils/pumps over?
My first reaction is that your boiler is probably over rated for the heat required.
Many older boilers are ratable to suit the job.
You should get Kevin to come and service it and set it up to provide the optimum power.
Tony
Many older boilers are ratable to suit the job.
You should get Kevin to come and service it and set it up to provide the optimum power.
Tony
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boiler stat failure is only lijkely to happen really if there is no room thermostat installed, as with a room and cylinder stat the temperate shouldn't and won't get up to boiler stat temperature anyway, it will shut off before that. the water in the pipe will get to about 80ish and the boiler stat will be at 85 ish, and the room stat temp will shut switched live/power to the boiler stat off before boiler stat temp is reached.
N
namsag
Steved101 , dont talk nonsense a boiler can get up to over 100 in less than 15 mins minutes depending on system or what is actually calling for heat . It can take an hour plus for a room to get up to a temp that a room stat would cut it off or half hour for a cylinder stat.
Agile even if a boiler was over gassed that would not stop a boiler stat working correctly
Agile even if a boiler was over gassed that would not stop a boiler stat working correctly
A new alias for Dr Drivel I fear.
What a load of twaddle steved.
Boiler stats fail to work for many reasons, including a scaled up boiler.
Ok tell me how a boiler being scaled up can cause a boiler stat to fail?? Yes the boiler may cycle on and off quicker and the water not get to temp, but the scale will not affect the stat's workings.
If a room stat is set to 21 as the norm (80 plus in the pipes), and the boiler stat a little higher as the norm, then if the boiler stat fails, the room stat will break the circuit/power to the boiler's switched live BEFORE the boiler stat temp is even reached.
If i am wrong here then please explain why and I will hold my hands up and apologise
If a room stat is set to 21 as the norm (80 plus in the pipes), and the boiler stat a little higher as the norm, then if the boiler stat fails, the room stat will break the circuit/power to the boiler's switched live BEFORE the boiler stat temp is even reached.
If i am wrong here then please explain why and I will hold my hands up and apologise
Boiler stat and roomstat can happily fail independent of each other. There are various reasons why a failing boilerstat would overheat the system even with a perfectly working roomstat.
All but 1 rads closed.
Boiler scaled up.
System sludged up
Manual bypass to far open.
Pump failing.
.........
bengasman, ok fair enough i never thought of it that way. So basically, if a boiler stat fails, it is more than likely that another system fault is present and needs looking in to?
don't you mean manual bypass too far closed??
don't you mean manual bypass too far closed??
how will it the boiler water temp will hit boiling point dam site quicker than your room will heat to 21 degrees.
bullshyte really does baffle brains
seco, if that were true then the room stat would not be doing anything ever. and the boiler stat would be constantly be cycling on and off. thus the reason for the room stat!!!
bengasman: explain how all but 1 rad closed or a scaled/sludged up boiler / failing pumo would cause the boiler stat to oerheat?? it would just reach temop quicker and cycle on and off, not fail completely...
bengasman: explain how all but 1 rad closed or a scaled/sludged up boiler / failing pumo would cause the boiler stat to oerheat?? it would just reach temop quicker and cycle on and off, not fail completely...
what you going on about.
room stat takes temp from the room not the water
namsag has already been over this.
room stat takes temp from the room not the water
namsag has already been over this.
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