Vokera gas boiler possible boiler/controls issue

[gmc600]

Hoping someone familiar with Vokera controls and boilers can help. I have a Vokera Mynute i20 gas boiler and recently noticed that some of the time the room thermostat is calling for heat but the boiler doesn't come on. It doesn't happen all the time just intermittently, any idea what the potential causes could be? At first I thought it was something to do with it being relatively warm earlier in the month and the outdoor temperature sensor stopping the boiler from coming on but it's now much colder outside and I'm still seeing the same behaviour.

Thanks

 

[gmc600]

thermostat asking for heat…

 

[gmc600]

…but boiler stays off

 

[gmc600]

Note that upstairs zone (controlled from a separate panel) is working fine.

 

[gmc600]

So now it seems to come on when programmed some but not all of the time, switching it on and off a few times on the programmer usually works, programmer fault? Connectivity fault to thermostat?

 

[vulcancontinental]

If the boiler is working some of the time it sounds like a controls issue and if one zone brings it on and another doesn't I'd start looking at the motorised valve controlling the zone concerned.

 

[CBW]

Do you know what zones valves you have?

 

[ianmcd]

It wil be that Danfoss thermostat, have changed many for that exact fault, you can actually buy the same thermostat and just un-clip the old one and clip the new one on , no wiring required , 2 min job, but make sure you turn the power off first

Amazon.co.uk

 

[gmc600]

Do you know what zones valves you have?

Yes danfoss type HPA2 for the downstairs one, upstairs one looks the same.

 

[gmc600]

It wil be that Danfoss thermostat, have changed many for that exact fault, you can actually buy the same thermostat and just un-clip the old one and clip the new one on , no wiring required , 2 min job, but make sure you turn the power off first

Amazon.co.uk

Thanks Ian, did exactly that and now it's working fine.

 

[ianmcd]

Thanks Ian, did exactly that and now it's working fine.

Thank you for the feedback, so many are not so gratefull and just take the unpaid help they get from here for granted, if it was my house and you have two of them , I would buy another 1 or 2 at around a tenner you are sorted, they do tend to fail and I have been told they will be discontinued soon, as you have found out very simple to swap over

 

[gmc600]

Hello again, I'm now having a similar issue again but this time the boiler is also refusing to heat the hot water or upstairs zone (which is controlled by a different type of thermostat). Tried switching it on and off and still nothing. Oddly the boiler came on after I got frustrated and gave it a dunt!

The behaviour of this boiler has been quite strange, works fine 99% of the time but I did notice a few weeks ago that early in the morning when I switch on the hot water by pressing the boost button on the downstairs heating/HW programmer it sometimes refuses to come on to heat the hot water (CH was fine and eventually it did start to heat the water but took about 30 minutes to get started - I can see the water temperature on a little display next to the HW tank). Today was the first time it refused to operate for either heating zone or the water. Any advice in case this happens again?

 

[Madrab]

might be an idea to have the zone valves/wiring checked to rule that out. Zone valve microswitches can get temperamental the older they get.