Glowworm boiler really hot water

[scantronic]

hi all
I have a glowworm back boiler I believe it's a 240 model (it's very old) anyway it's working fine well a little too fine as the hot water from the cylinder is ridiculously hot as are the radiators, the boiler thermostat is set to just above minimum but still the house gets very warm. If it's fine how it is I don't mind leaving it I'm just concerned it may cause damage to some part of the system, does the tank thermostat connect to the boiler?

Thanks in advance

 

[45yearsagasman]

View media item 86934Do you have a cylinder thermostat similar to this? It's best to determine the type of system you have before giving advice. From what you say , I would suspect your boiler stat has failed.

 

[scantronic]

Thanks I will have a look tomorrow and the boiler does stop for about 10 minutes then runs again like it's got up to temperature but I'll have a good check tomorrow

 

[Agile]

Can you turn the boiler stat any lower?

Sounds as if its a gravity hot water and the boiler stat is rather out of calibration.

Tony

 

[scantronic]

I guess I probably could I'll try it tomorrow I just don't want it to break down because it's going to be very hard if practically impossible to replace it for a wall hung

 

[TCCHeating]

I guess I probably could I'll try it tomorrow I just don't want it to break down because it's going to be very hard if practically impossible to replace it for a wall hung

Don't worry. They're very reliable boilers. Dont let anyone try and sell you a new boiler. Sounds like you just need a new thermostat. Call an engineer out to replace it. Shouldnt be an expensive repair

 

[scantronic]

Ok it's been like this for years so I'll finally get it sorted soon I'll try looking for a cylinder thermostat if not I'll turn the boiler one right down
Thanks for all your advice

 

[bhm1712]

I had this problem when I moved into our first home. It was a gravity hot water system with a glow worm boiler. The hot water has to be on for the heating to come on - boiler stat failed at maximum and the hot water would get up to about 85 degrees even if the stat was turned to minimum. A new stat fitted by our friendly plumber and all was well.

If it is a gravity hot water system then fitting a cylinder stat is not an option unless the system is converted to a C plan setup as a minimum. This involves fitting a motorised valve into the hot water pipe work from the boiler (but after the feed and vent) and having the controls circuit rewired to include a cylinder stat plus the capability to send an on signal to the boiler from both the hot water and central heating command.

 

[scantronic]

Thanks for all the replies I've turned the stat down to minimum and it's cooled down a but so it's not scalding obviously it still needs a new thermostat so I'll get it done after Christmas because I don't want it to pack up

 

[petit_pablo]

Good luck finding spares that boiler must be 40 odd years old now if its the old cascade 240!

 

[bhm1712]

Parts readily available especially the thermostat. Average price £49

 

[dreadnoughtheating]

I have just one 240N Capricorn on my books, round here, I think they were outnumbered by the Bermuda range by 5 - 1

 

[scantronic]

Yeah it's about 40 years old now and the gas fire looks a bit tatty aswell actually where could I get a new fire for it?

 

[dreadnoughtheating]

New fire? Not very likely.....

Budget for a new boiler, and look on it as an 'investment'

 

[scantronic]

It would be very difficult or nearly impossible to move the boiler from the living room to the kitchen or utility room/garage and I have no wall space really in my kitchen I dread to think how much it would cost aswell, the current fire still works fine in fact it's on right now aswell as the boiler it just is beginning to show its age