Evohome assumes you need one BDR91 for the HW and the other to fire the Boiler as a Boiler Relay. If you have a true S plan then you will land up with 3 BDR91s. One for HW, one for CH and one for Boiler. Ofcourse you could choose to use an OT bridge instead of a Boiler Relay and then have the two BDR control the HW and CH valves only.
Completely new heating install, best way to configure for EvoHome?
Collapse
X
-
Originally posted by bruce_miranda View PostEvohome assumes you need one BDR91 for the HW and the other to fire the Boiler as a Boiler Relay.
If you only have a hot water zone valve and no heating zone valve (in which case it's not really an S-Plan or Y-Plan system) then yes you can configure the two BDR91's as hot water zone valve and boiler relay instead, and let the HR92's prevent heating during hot water demand, provided all radiators have HR92's.
If you have a true S plan then you will land up with 3 BDR91s. One for HW, one for CH and one for Boiler.Last edited by DBMandrake; 5 February 2017, 09:56 PM.
Comment
-
-
The reason I said Evohome assumes one BDR to work the HW and one to fire the boiler is because that's how it comes configured in the box. To use the Boiler relay to work the CH valve instead you need to unbind it as the Boiler relay and rebind it as the CH zone valve relay.
Evohome expects all your radiators to have HR92s with no separate CH zone valve.
Comment
-
-
Originally posted by bruce_miranda View PostThe reason I said Evohome assumes one BDR to work the HW and one to fire the boiler is because that's how it comes configured in the box. To use the Boiler relay to work the CH valve instead you need to unbind it as the Boiler relay and rebind it as the CH zone valve relay.
Evohome expects all your radiators to have HR92s with no separate CH zone valve.
Comment
-
-
Originally posted by paulockenden View PostI know this isn't what you want to hear, but Evohome works best when you give it control of everything. I think that when spending the amount you must be, it's daft to skimp on a couple of hundred quid for additional HR92s.
However, if you do that, a couple of things to note:
1 - You won't actually need the four zone valves (so perhaps a saving can be made there to pay for the HR92s?).
2 - You'll probably need to have the controller on one of the middle floors, to get a reliable signal to the top floor and your basement. Ideally somewhere in the middle of that floor too, rather than on an external wall.
As for the 12 zone limit, you can put several HR92s (or even rooms) into the same zone. So you could have a 'bathrooms' zone, for example, or 'second floor'.
I'm sure others will have observations too....
P.
Comment
-
-
Originally posted by Bovrilelles View PostDoes this mean the combination of EvoHome BR91 and HR92s on a S Plan dual valve system will effectively zone?
Or are you talking about an S-Plan plus system with more than one heating zone valve, for example to different floors ?
As for zoning - if you fit HR92's to all radiators then your house is fully zoned (regardless of whether you have any heating zone valves) as every zone on the controller can be scheduled and controlled independently and all are capable of calling for heat from the boiler. EG There is no one specific zone that always has to be heating to get heat elsewhere, such as a room stat in a hallway on a traditional system where if that hallway isn't calling for heat no other rooms can get heat. (One of my pet peeves with a traditional single thermostat and manual TRV's system)
Comment
-
-
S-plan plus is redundant with Evohome as the TRV’s do the zoning for you. You’d just end up wiring all heating zone valves to come on together anyway as evohome does not have the ability (or need) to independently control multiple heating zone valves for HR92 radiator controller zones.
In fact it’s possible to configure an S-plan system without any heating zone valves with evohome (just one for hot water) as long as all radiators have HR92’s, although there are some minor disadvantages to doing that if your boiler boosts flow temperature for hot water reheating.Last edited by DBMandrake; 22 November 2018, 07:22 PM.
Comment
-
-
Originally posted by DBMandrake View PostS-plan plus is redundant with Evohome as the TRV’s do the zoning for you. You’d just end up wiring all heating zone valves to come on together anyway as evohome does not have the ability (or need) to independently control multiple heating zone valves for HR92 radiator controller zones.
In fact it’s possible to configure an S-plan system without any heating zone valves with evohome (just one for hot water) as long as all radiators have HR92’s, although there are some minor disadvantages to doing that if your boiler boosts flow temperature for hot water reheating.
Boiler been offline for the duration of the day and now not sure controller is communicating with BDR91. Do you know how I can do a factory re-set and re-bind to my controller? (In layman’s terms?!)
Comment
-
Comment