Reply With QuoteUpdate received, I'm running now the 19.33Originally Posted by oxygen
Yes. Or sometimes I've noticed the actuators open but the boiler doesn't run. Just seems like it does a lot of "fuzzy" logic, that is messing around too much. Sometimes even when it is a couple of degrees off the setpoint it can switch off the pumps and actuators for 5 minutes (which really doesn't help anything). With a pretty well setup flow rate it doesn't need to modulate things as much as it seem to try.
An example this evening. Temperature setpoint 21C. Room nicely constant at that temperature. Wife says she's abit cold so I knock it up to 23C. UFH pump activated and actuators open. 5-10 minutes later they switch off. I look on the Evohome and it says the UFH demand is 49% (presumably why it is cycling the pump and actuators). That's just nonsense as UFH doesn't respond to a 2C increase in room temperature by cycling on/off every 5-10 minutes!
Last edited by simonh29; 3rd December 2020 at 10:34 PM.
Update received, I'm running now the 19.33
I hope the new firmware fixes the intermittent locking up problem.
The clock on my unit stopped at 5:22 this morning and the heating didn't come on.
I had to disconnect the batteries to get it going again.
Brrrrrrrrr!
I take it you're not on 19.31 or 19.33 ?
That's a well known problem on older firmware versions (discussed a lot on this forum) and it has bitten me personally twice, but it's a long time since it last happened to me, maybe a couple of years.
Has anyone had this clock stall happen on 19.31 or 19.33 ? I haven't, but because its so long since it last happened prior to switching to the beta firmware versions I'm not sure that proves anything.
Not happened to me.
No I'm not on the beta firmware.
It's happened four or five times to me.
I've had to disable load scaling again (This time from partial)
The Lounge will not reach its setpoint.
Despite a 49% demand for this zone and some demand for other zones the boiler demand is 3%
I've attached a shot of the System Summary with load scaling enabled together with the System Parameters.
Then I've attached a System Summary after Load Scaling is disabled.
@Atm Is there any obvious reason why this is affecting me in this way?
There was another zone on the second screen that only required 2%
I've been monitoring things via Domoticz and the RGI80. I think the UFH control and the Evohome are almost like two separate things. Basically, the UFH is a TPI controller and so the room will be set to 30% and switch on/off to achieve that. The OpenTherm boiler will then be set to say a level and that will do it's own thing, sometime it even gets switched to 10% or so which turns off the boiler altogether while the floor controller is still on/off at a certain interval. Sometimes, it will fire the boiler at 100% which is silly considering it is UFH and doesn't need such high temperature delivering to the mixing valve on the manifold.
I'm not sure what knowledge the Evohome has of the UFH control. It seems to treat it more like you would a radiator valve with hot water rather than a long slow warm water device. I don't know why it doesn't have any UFH Water Temperature setting where it could act more wisely in understanding how high to fire the boiler when the UFH is the only thing calling for heat, and it also seems to drop the UFH manifold % far too low too quickly when a bigger 2C heat requirement is needed.
It is for all these reasons that I didn't bother with the UFH controller, besides the fact that in my case the entire manifold is serving one large generally open plan area. The real benefit would have been lower flow temperatures for UFH but that doesn't appear to be the case. But I'm not entirely happy with the BDR91 running the UFH either because of its inbuilt TPI functionality that I cannot turn off.
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