Some Help Please With Multiple Zone Valves On Evohome

[Edinburgh2000]

With the BDR91 do I have to go to the hassle of using a wireless thermostat or can I just put a cheapo wired one in the system?

No. You need to use a kosher Honeywell thermostat that reports an analogue temperature signal to the controller, not a binary on/off temperature demand. The Honeywell system is designed to manage temperature over a range, such that it throttles the heat input as a zone approaches its setpoint temperature. With a zone valve, the Evohome system then applies an analogue-to-digital conversion (e.g. 25% heat demand = off for 15 mins; on for 5 mins), which is referred to as "TPI" in this forum. Your Evohome controller (and the web and phone apps) will report the setpoints and actual temperatures in each zone, and you need Honeywell thermostats to report the actual temperatures.

[Chunky]

No. You need to use a kosher Honeywell thermostat that reports an analogue temperature signal to the controller, not a binary on/off temperature demand. The Honeywell system is designed to manage temperature over a range, such that it throttles the heat input as a zone approaches its setpoint temperature. With a zone valve, the Evohome system then applies an analogue-to-digital conversion (e.g. 25% heat demand = off for 15 mins; on for 5 mins), which is referred to as "TPI" in this forum. Your Evohome controller (and the web and phone apps) will report the setpoints and actual temperatures in each zone, and you need Honeywell thermostats to report the actual temperatures.

Okay thanks for that. It's more complicated than I wanted but I can live with it.

[bruce_miranda]

You can have a zone report only temperature but no BDR91 but the reverse is not possible. It used to be possible with the Honeywell Hometronic but not Evohome.

[dst]

Hiya,

you can use BD91 to control any number of the zones (up to the max of 12).
The BD91 can be added as a few types of zone (note you'll need a separate thermostat to get the zone temp):
- Electrical underfloor - it just switches electrically
- Zone valve - it switches electrically (to operate the valve) AND requests heat from the boiler

For any of your zones use the second option, this'll then mean they'll pull for heat from the boiler. You say you don't want thermostatic control in some of your zones, how come? Surely it's better to keep them regulated rather than full heat continuously?

I'm about to get UFH (CH based) in my kitchen and this will also be done using a BD91 rather than the very very expensive HCC80R - this is because the UFH kit I'm going to buy (from these guys www.theunderfloorheatingcompany.co.uk) already has a mixer and pump, so all the BD91 needs to do is know when to request heat from teh boiler, the UFH kit then does the mixing.

Hope that helps

thx

Hi,

Can anyone provide further information on how to set up as above - 'Electrical underfloor - it just switches electrically'

I want to use a BDR91 to switch the pump on the UFH manifold, but don't want it to call for heat from the 'boiler' (or in my case thermal store)

How do I bind the BDR91 to get this behaviour? The only option I see is Underfloor Heating, not Electric underfloor heating and I couldn't get it to bind to the BDR91 under the UFH option!?

Any help appreciated.

Regards,
Scott.

[dst]

Hiya,

you can use BD91 to control any number of the zones (up to the max of 12).
The BD91 can be added as a few types of zone (note you'll need a separate thermostat to get the zone temp):
- Electrical underfloor - it just switches electrically
- Zone valve - it switches electrically (to operate the valve) AND requests heat from the boiler

For any of your zones use the second option, this'll then mean they'll pull for heat from the boiler. You say you don't want thermostatic control in some of your zones, how come? Surely it's better to keep them regulated rather than full heat continuously?

I'm about to get UFH (CH based) in my kitchen and this will also be done using a BD91 rather than the very very expensive HCC80R - this is because the UFH kit I'm going to buy (from these guys www.theunderfloorheatingcompany.co.uk) already has a mixer and pump, so all the BD91 needs to do is know when to request heat from teh boiler, the UFH kit then does the mixing.

Hope that helps

thx

Hi,

Can anyone provide further information on how to set up as above - 'Electrical underfloor - it just switches electrically'

I want to use a BDR91 to switch the pump on the UFH manifold, but don't want it to call for heat from the 'boiler' (or in my case thermal store)

How do I bind the BDR91 to get this behaviour? The only option I see is Underfloor Heating, not Electric underfloor heating and I couldn't get it to bind to the BDR91 under the UFH option!?

Any help appreciated.

Regards,
Scott.

[billytkid]

Hi,

Can anyone provide further information on how to set up as above - 'Electrical underfloor - it just switches electrically'

I want to use a BDR91 to switch the pump on the UFH manifold, but don't want it to call for heat from the 'boiler' (or in my case thermal store)

How do I bind the BDR91 to get this behaviour? The only option I see is Underfloor Heating, not Electric underfloor heating and I couldn't get it to bind to the BDR91 under the UFH option!?

Any help appreciated.

Regards,
Scott.

Hi Scott,

what versino of the EvoHome controller have you got? I'm fairly certain mine has the option of Electric Heating (or something similar) on the zone setup. I'm not home until Thursday but can check then.

Thx

[dst]

Hi,

Thanks for coming back to me on this. I posted my question on another related thread as well, which now has more detail than this one:

https://www.automatedhome.co.uk/vbul...8961#post38961

Called Honeywell earlier today so hoping to return to find an upgraded firmware on my controller tonight!

[billytkid]

Hi,

Thanks for coming back to me on this. I posted my question on another related thread as well, which now has more detail than this one:

https://www.automatedhome.co.uk/vbul...8961#post38961

Called Honeywell earlier today so hoping to return to find an upgraded firmware on my controller tonight!

Morning,
I checked last night and this does indeed look like a FW issue, my controller does have an electric heat zone setting.

thx

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