Same again here. And this time not to do with optimum start. Maybe it coincided with optimum stop... uncertain on that. Either way it’s ideal.Quote:
Originally Posted by roydonaldson
That’s at least 3 of us with this issue now so hopefully they might be able to gather enough information to work out what is going on... Andy?
I have a similar setup here. Hot water is not under the control of evohome - I retained the old programmer for that, initially due to cost and then partly because of the issues some reported here. It didn’t seem to offer enough additional usability to be worth the outlay.Quote:
Originally Posted by mtmcgavock
So I just have a single bdr91 as a boiler relay. Our boiler was an ancient ideal Mexico and I added the overrun timer for 2 reasons. One because it seemed that there was a lot of latent heat in the boiler going to waste (through the flu and into the cupboard that the boiler was housed in). Also because the constant cycling of the pump and CH valve was annoying.
We have recently had the boiler replaced with a WB which has its own pump and overrun. I have retained the timer circuit simply to hold the valve open for long enough for the boiler to complete its overrun and also to stop the valve cycling when the tpi is at its lowest setting.
As described above I have also arranged so any HW demand will cause the CH valve to close immediately that there is no TPI demand. When the HW demand is satisfied, the overrun is diverted back through the CH circuit.
All our roads either have HR92 or old fashioned TRVs so there is little or no undesired hearing in the summer, although it does mean that the bathroom towel rails get warm in the mornings which is useful for drying towels in the summer and means we don’t have to use the electric side of the rails. At least it did with the old boiler and it’s massive heat exchanger. It remains to be seen if the new boiler will retain enough heat to make any real difference.
Happy to post the schematic here is it is useful to anyone.
I have no heat in the downstairs of my house. All downstairs zones are below there setpoints, EvoHome controller shows all these zones calling for 100% heat, yet the BDR91 zone valve at the boiler is off and has been for the last 2 hours.Quote:
Originally Posted by AlexP
Andy - can someone please look at his urgently.......or revert my controller.
Thanks, yes it's something I need to do as had been thinking it for a long time and it looks like a few members have done this.Quote:
Originally Posted by AlexP
Mines a little more complex though, as I have 2 heating zones (Rad & Towel Rail Circs), along with HW. On top of that I have HW priority which I can turn on and off as required, then I can have the Towel Rail zones coming on with the HW via a relay in summer (Again selectable for On/Off).
So think i'll have to have a sit down and think of the best way of doing this, it isn't as simple as just adding a timer in. And as DBmandrake and yourself say you want the CH valve to close on a HW demand.
Just for feedback - no issues with set points at my end so far.
Well in my case I don't just want the CH valve to close on hot water demand - because that would be hot water priority, which I don't want. I just want it to come back under TPI control from the heating relay.Quote:
Originally Posted by mtmcgavock
The reasoning for my arrangement is that when there is no hot water demand the boiler relay will cycle on and off with TPI based on heating demands - in this condition I want the heating zone valve to remain open to allow continuous water flow to radiators (ignoring the heating relay TPI) while the boiler cycles on and off with TPI to modulate heat output.
However during a hot water reheat cycle the boiler relay will turn on continously regardless of heating demand, in this condition I want the heating zone valve to revert to TPI modulation so that despite the boiler running continuously and reaching its flow temperature set point heat transfer to the radiators can be modulated down to approximately what it was before by making the flow to them intermittent under TPI control.
The flow temperature is higher but the intermittent flow should cause total heat transfer to roughly even out, and this is better than just letting it flow continously during a hot water reheat (radiators will go over temperature due to increased flow temperature) or shutting it down completely like hot water priority. (Radiators wil go cold over time and newly opening radiators won't heat up as in the bathtub scenario..)
Sorry, This is actually the setup I have too - I just worded it badly. I think essentiallly we have the same logical setup.Quote:
Originally Posted by DBMandrake
Think you’ve misunderstood me too - I was meaning when there’s a HW demand and no CH demand. You don’t want the CH valve open on timer then, during a dual demand (HW & CH) then yes you’ll want both open - if you haven’t got HW PriorityQuote:
Originally Posted by AlexP
No problems seen so far with the new firmware and my OpenTherm, DHW priority, UFH mixer valve setup.
New features appear complementary to my OTGW based weather compensation, which is good.
@Andy the Minion,Quote:
Originally Posted by Andy the Minion
I am the maintainer for the evohome (actually the TCC) integration for Home Assistant
On my to-do list, due to repeated/high demand from people using the integration, is to emulate an economy mode with a variable offset, from (say) 1-3 C.
In short, 3 C is too much, and thus economy mode is not being used as much as it might me.