Ecotec 637 System Boiler - Is this correct behaviour?

pghstochaj · May 15, 2017

Hi everybody,

I have just had an Ecotec 637 system boiler with Unistor 300 tank installed. These are controlled using the Evohome system although I haven't yet bought the TRV heads so it is just working as a single thermostat control.

Everything is working correctly in that the thermostat is calling for heat (HW or CH) and the respective valve is opening and telling the boiler to fire. The boiler goes through its start up cycle, the burner lights and stays at 50% for about 2 seconds and then modulates right down. The water temp in the boiler during this period will be around 30degC and maybe 15 minutes later the boiler modulates up and then runs fine. If I turn the boiler on and off then it skips this 15 minute wait and modulates straight up.

Is this behavior normal and this boiler is just slow to react, or is something else happening?

I don't want to call back my installer just yet, until I know whether something is wrong or it is just my ignorance.

Sorry if I have missed anything out from the above, just let me know and I will answer it. Regarding the boiler size, it's a large house and the boiler is appropriately sized.

Cheers

oz-plumber · May 15, 2017

I would call the installer back.

They either have not set the boiler up correctly or there is a fault with something within the boiler.
Your installer should know what to do - repair or call manufacturer for assistance

Chalked · May 15, 2017

Hi
Get the Electritian back. It's wired wrong ( missing permanent live)

pghstochaj · May 15, 2017

Thanks both. Regarding the perm live, the boiler stays on even if the evohome doesn't send out a signal, is this still the correct problem?

pghstochaj · May 17, 2017

Hi, any help on the perm live issue above please? I want to guide the fitter to the solution if it is well known.

Thanks
Paul

Chalked · May 17, 2017

It's either perm live missing, or the "on" link still installed. Any Electritian will know.
As it's inside the sealed casing on a gas burning appliance. We can't give advice on this.
Hope you understand our legal and safety responsibilities here.

pghstochaj · May 17, 2017

Hi, thanks for the reply. If it is turned on and off quickly it seems to bring the burner in quickly at a high rate which may make the problem difficult to replicate when he comes - I've just made me question myself as it hasn't happened this evening during my testing! Anyway, I've messaged him and I'll let you know how it gets sorted.

Thanks for your help - I understand the limitations. I am a chartered process engineer working in power station design and project management so I understand the equipment and risks, but am obviously not gas safe registered which is what matters in this instance.