Hi,
Please can someone help me with a thermostat question. I've spent a fortune on a plumber and i'm still not sorted.
Long story short - I have a gloworm combi boiler and a honeywell CM907 thermo. 3 yrs old, all working fine until recently. I noticed that in the evening, during the programmed setting, the thermo would be set to 21 degrees. The room temperature 19. The boiler would fire up, reach 20 or 21 for example and all the radiators would be warm. About an hour later, i'd suddenly notice the house had gone cold. I check the thermostat it shows a room temp of 20 and the "flame" symbol is still on (because the pre-set temperature is asking for 21) but the boiler is not fired up and all the rad's are now cold. (Same thing in the morning when it's on).
My first thought was that this is the honeywell "cycling" (?) and not firing up because it's 0.5 - 1.5 degrees close to the preset temperature. Fine, but then the house was cold, so i changed the setting up to 23 degrees to increase the demand and make it fire up, but nothing. I wait ten minutes (because i read somewhere about ON/OFF cycles) try again, and it fires up fine.
Ok, so maybe this is how it's meant to operate (really?) but then how do I avoid the problem of having it on for an hour, not reaching the temperature and then clocking off.
What am I doing wrong?
In the meantime, i got a plumber to fit a new thermostat and i'm having all the same issues - which means a) i've wasted money and b) there was never a problem in the first place?
Also, the new thermostat seems to read the actual room temperature as about 3 degrees higher than the old one, so all my settings need to go up by the same - why is this, has the installer done something? (he said he didn't use any temperature offset).
Any help from the experts greatly appreciated.
Please can someone help me with a thermostat question. I've spent a fortune on a plumber and i'm still not sorted.
Long story short - I have a gloworm combi boiler and a honeywell CM907 thermo. 3 yrs old, all working fine until recently. I noticed that in the evening, during the programmed setting, the thermo would be set to 21 degrees. The room temperature 19. The boiler would fire up, reach 20 or 21 for example and all the radiators would be warm. About an hour later, i'd suddenly notice the house had gone cold. I check the thermostat it shows a room temp of 20 and the "flame" symbol is still on (because the pre-set temperature is asking for 21) but the boiler is not fired up and all the rad's are now cold. (Same thing in the morning when it's on).
My first thought was that this is the honeywell "cycling" (?) and not firing up because it's 0.5 - 1.5 degrees close to the preset temperature. Fine, but then the house was cold, so i changed the setting up to 23 degrees to increase the demand and make it fire up, but nothing. I wait ten minutes (because i read somewhere about ON/OFF cycles) try again, and it fires up fine.
Ok, so maybe this is how it's meant to operate (really?) but then how do I avoid the problem of having it on for an hour, not reaching the temperature and then clocking off.
What am I doing wrong?
In the meantime, i got a plumber to fit a new thermostat and i'm having all the same issues - which means a) i've wasted money and b) there was never a problem in the first place?
Also, the new thermostat seems to read the actual room temperature as about 3 degrees higher than the old one, so all my settings need to go up by the same - why is this, has the installer done something? (he said he didn't use any temperature offset).
Any help from the experts greatly appreciated.
