Time switch on Combi Boiler in Loft

[Bowness72]

Hi there,

I've got a slightly confusing situation with a remote thermostat and an analogue time switch on a combi boiler. The boiler is in the loft so its a pain to adjust the time manually. It has one of the old style time switching clocks which I have set but apparently the boiler seems to still be running during the night. It's not my house so it's not quite as easy for me to check when its on and off. On the clock there is also a switch which can be set to "on", "off" or "auto". It had been set to "on" when installed which I guessed was why it was still on during the night, presumably because the thermostat was calling for heat. I tried switching to "auto" believing this would then mean it was on and off at the appropriate times, but I'm thinking that would mean it couldn't be switched on manually by adjusting the thermostat if it gets a bit nippy ?

Does that make sense ? and that its supposed to be left "on" but then just controlled purely by the thermostat ? or am I missing something. Like I say, its not my boiler so haven't got my head around the problem fully.

Thanks for any advice

 

[petertheplumber12]

your thinking is right the time clock will be on continually when on, auto will be be time clock on and off times, and off no heating at all. I would suggest putting it on continuous or ON and turning heating up and down on thermostat. down at night to about 15C and up when you want heat to 20C or whatever.

 

[Bowness72]

Thanks Peter, there are also TRV's on the rads and I'm not sure how they integrate with or override the remote thermostat ?

 

[mikely]

It would be preferable to replace the thermostat with a programmable type so that the timer can be left permanently ON, or removed. The programmable thermostat will then control heating times and temperatures.

 

[petertheplumber12]

It would be preferable to replace the thermostat with a programmable type so that the timer can be left permanently ON, or removed. The programmable thermostat will then control heating times and temperatures.

I agree mikely, but he said it was not his property so I gave him the next best option.

 

[petertheplumber12]

Thanks Peter, there are also TRV's on the rads and I'm not sure how they integrate with or override the remote thermostat ?

There should be a bypass arrangement and the room that has the thermostat should have no trv or it should be wide open. So using the settings on the trv's you can control individual room temperatures

 

[CBF]

& this time of yr it will prob be running all nite on the boiler frost stat, IMO it's a completely stupid idea to put a boiler in the loft

 

[Bowness72]

Is installing/synchronising a programmable timer a DIY job or does it involve opening up the boiler ?

 

[mikely]

Installing a programmable thermostat is quite simple but does involve connecting to mains voltage wiring. It can simply replace the existing thermostat, so there is no need to touch the boiler.

However, from your original description it is not entirely clear what the problem is you have now. With your system as described, the timer should be set to AUTO and then the heating should be on during the timer on periods and controlled by the room thermostat during those periods. Does this not work?
As mentioned before, if the timer is set to ON, then the heating will be on all the time controlled only by the thermostat.