Hi
We are currently planning a kitchen refurb but as part of that, we will lose two panel radiators (which are in our 'Kitchen' zone with HR92's on each). I am planning on using kickspace/plinth heaters instead but we'll obviously lose control of the heating in that zone, and I wondered whether there was any way to integrate a zone heated by kickspace heaters into an Evohome setup (whether it is elegant or not).
Any idea's?
I don't think underfloor heating would provide anywhere near enough heat to replace the two units or I would choose that option and an UFH controller so my options are limited. Some of the Myson kickspace heaters can be controlled remotely (wired remote) and I was wondering if that could be incorporated into the Honeywell UFH controller in any way, or simply to add the HR92's to the pipework of the heaters themselves to still give some level of control.
Yes I started to look into this, so I have a BDR91 spare (as my boiler already had one of the older relays so didn't need updating) - if that is wired to the fan it will simply power the entire unit on/off on the control of the wireless thermostat in the room? Actual flow through the pipes however will be determined by any other zone calling for heat I would guess, so there will always be residual heat if there is another zone calling for heat, which I don't think is an issue.
If I have two heaters in the room, that would be two BDR91's? Can a single room stat control multiple BDR91's and is there a limit to the number of relays the Evohome controller can support?
I'm just trying to visualise what it would look like on the display - at present, the two HR92's are grouped into a single zone called 'Kitchen' - could the two BDR91's be grouped similarly?
Couldn't you just add a Zone valve into the kitchen, after your zone valve have your two kick space heaters. Wire the BDR91 to the zone valve motor (You don't need a S/L to the boiler as you have your boiler relay). Have a thermostat on the wall, and program the kitchen as zone which is controlled by a zone valve and thermostat. When the zone calls for heat the BDR91 will click on, your boiler relay will click on, then the fans on the kick spaces will power up when the flow temperature is hot enough. Simple.
It is basically the same issue as I had with my towel rail circuit.
No my suggestion is to have a second BDR91 with the zone valve. The only thing you'd need at the valve then is power.
I had the same issue with my towel rails as I didn't want TRVs on them. So they are on a separate zone valve which is controlled by a wireless stat and BDR91. When you add a zone in the Evohome it will allow you to add it as controlled by a zone valve.
Are you on a traditional system or a combi?
It's a combi
Something to keep in mind with this approach is a BDR91 configured as a zone valve for a zone will perform TPI modulation - so when the temperature is near the set point it will switch on and off in every (by default) 10 minute cycle.
Whether this is a problem or not depends on whether the fans mind being constantly switched on and off or whether they make enough noise that them stopping and starting would annoy you!
So you will just need your additional relay wired to the zone valve and leave your BDR91 as a boiler relay like you currently have it.
Yes DBMandrake is correct it will use TPI, so whether this annoys you or not will be up to you. I have mine set on 3 cycles an hour so that it reduces this issue. Also the fans will only run when the flow temperature is there not when the thermostat clicks on/off.
Can you change the cycles per BDR91 used as a zone valve?