Heating not firing up with thermostat

[Crazymoose565]

We have a vokera easi heat 25ci boiler and a channel plus H17XL thermostat.
the thermostat is set for the boiler to come on at certain points in the day I.e morning and evening, the thermostat light comes on at the correct times and screen shows heating is on but the boiler isn’t coming on (although the thermostat says it is). I’ve reset the thermostat and still doesn’t work.
Had a read through the boiler manual and it doesn’t explain the different settings on the actual boiler screen. It’s like the thermostat and boiler and working in sync.
Does anyone have any ideas?

 

[ericmark]

Boiler type would help, my oil boiler is either on or off, it does not modulate, to run two things are required, one the thermostat on the wall is calling for heat, and two the return water is cool enough.

So the thermostat at moment set to 20ºC and the room is reporting 19ºC so thermostat is showing orange when means asking for heat.

However if I look at the TRV heads, hall is target 15ºC current 16ºC so that radiator should be turned off, only 4 out of 14 TRV heads show current so not sure how many asking for heat, but boiler is cycling on/off as clearly not all TRV's are open.

With gas the boiler can often modulate (turn down) so is running but not flat out, but you have not said if boiler oil, gas, or solid fuel, or what controls are on the boiler, although my thermostat with my boiler turns on/off, the same thermostat with a gas boiler could turn the boiler up/down, which is far better if available, so one would need a lot more info to answer really.

 

[stem]

We have a vokera easi heat 25ci boiler and a channel plus H17XL thermostat.

The H17XL is a single channel timeswitch, not a thermostat.

The H17XL timeswitch should be wired in conjunction with a separate room thermostat. For the heating to operate, both the timeswitch (for on/off times) and the thermostat (for temperature control) need to be 'on'. Is the thermostat set at a high enough temperature?

 

[ianmcd]

as @stem says the channel plus H17XL is not a thermostat , it is a timeswitch, there will be a thermostst somewhere that isnt turned up

 

[Crazymoose565]

Hi

Thanks for the replies. Sorry for the confusion there is a thermostat next to the channel plus - it’s been turned up at 20 and the heating still hasn’t been coming on (house is cold) so I don’t think it’s that.

The channel plus flicks on at the time stated (red light comes on) and says the heating is on but the boiler isn’t. The boiler seems to have a green flashing light which I think means it’s in standby but it’s not triggering on. No amber or red flashing lights so assume there is no boiler error.
Boiler is gas combi. Hot water still runs no problem.

On the boiler panel there is a P1, P2, P3 on the bottom (seems to be on p3 at the moment) - but there is no explanation in the manual to what they mean. If you press the central button it flits between different screens (on/off/auto/time etc) so I think we are maybe on a wrong setting somewhere

 

[stem]

OK thanks. Provided that the actual temperature in the room where the thermostat is located is below 20C then the heating should have come on. You don't provide us with details of the thermostat, but if it's a battery operated model, have you tried fresh batteries?

Unfortunately I'm not overly familiar with your particular boiler. However, the way that boilers are controlled varies from installation to installation. Generally with a combi, the programmer is wired to the thermostat which is then wired to the boiler, such that when the programmer and thermostat are both 'on' the boiler starts the heating. Other installations have motorised valves installed. In this instance the programmer and thermostat are wired to that instead of the boiler. They open the motorised valve and when the valve opens it has a small switch inside that starts the boiler. A faulty motorised valve can stop that happening. Do you know if you have a motorised valve installed?

Generally though trouble shooting in this instance usually requires someone competent in the use of a multimeter and having knowledge of basic electrical circuits testing the wires at the programmer / thermostat / boiler to find out what's missing.

 

[ianmcd]

be very carefull in who you get to check out your problem, your boiler is low voltage switching, which can be altered via a relay that the manufacturer will sell, but if you let someone mess around that doesnt know what they are doing will be expensive

 

[ericmark]

but there is no explanation in the manual to what they mean

I did a quick hunt, I found this manual which may be the wrong one P1 talks about 30% output, but yes can't find P2 or P3 which makes me think maybe wrong manual, it shows wiring of the thermostat and time clock if fitted as @ianmcd says volt free, so need to be careful not to get mains connected, but if mine I would temp replace the link to rule them out.

I would be looking for a local heating guy as quick glance the set up seems complex, and if mine would not want to play with it. I note OpenTherm enabled and wonder why an on/off thermostat would be fitted?

 

[Crazymoose565]

Thanks everyone! Looks like I will have to admit failure and get someone out!