How to connect the Communication Module Follow
The Wiser system currently supports OpenTherm only in conjunction with a combi boiler and a 1 channel Wiser HubR.
If your boiler supports OpenTherm, follow the instructions below.
Existing OpenTherm Installation
1 Remove the OpenTherm cables from the existing controller or thermostat.
2 Remove the Communication module from the rear of the HubR
3 Set the OpenTherm cables into the Communication module. Cables can be wired any way.
4 Replace the Communication module into the HubR
5 Mount the HubR on the backplate. When OpenTherm connection is detected, Wiser Heat app will automatically set-up Communication modulation as control type without asking for any configuration.
Re-wiring to OpenTherm from standard installation
Any motorised valves must be disconnected and set to open. Then follow steps 2 – 5 above to wire in the Communication module.
If you are fitting a new system or require rewiring, contact an installer.
Comments
7 comments
If I want to use opentherm to control my boiler, will it work with my motorised trvs? Or as it says in the article, will they stay bypassed?
Hi Damm is this right? I just purchased a Kit 1 and 4 TRV's intending to use with OpenTherm connection to my combi boiler. Don't the TRV's communicate with the HUBr and it then communicates with the Boiler via OpenTherm? Or Do the TRVs only call for heat on the 230v On/Off contacts of the HUBr?
Also Is there supposed to be a diagram on this page. If so I can't see it does not display the .PNG
@steve mine works, but I'm not getting hot water, I might have to revert it back to non opentherm operation if I can't get a fix.
You're right the trvs demand heat from the hub and the hub talks to the boiler via opentherm
Got mine installed for just over a week now, As a Combi Boiler I only have the single channel HubR for the central heating. Hot water is on demand from the taps' so all good there.
The Opentherm connection was detected automatically by the HubR and seems to be working just fine.
Don't know how good the load balancing is without using some form of diagnostic gateway on the opentherm connection. But so far monitoring gas usage I say I'm going to save at least and third of previous usage! early days!
Clarified my original post with support, by motorised valves they mean zonal control valves not the TRV's.
Ah OK, I think my issue is down to my boiler (Navien NCB) not getting a demanded water temperature from my hubR so isn't heating the hot water. Everything else seems to be working though. I've opened a support ticket, and also in contact with the boiler manufacturer to see if there's a work around.
I'm using an Ideal Logic Max 24 conventional boiler with cylinder which is Opentherm. Having the same issue as Carl. CH is working fine, but HW call doesn't tell the boiler to fire up (pumps and valves all kick in as usual)
Update - I found my boiler had a 2nd switched live for hot water. Making sure that was wired in from the hot water relay on Wiser Hub along with opentherm, the boiler immediately knew what to do. I now have hot water priority, (extra hot to heat water tank) when only HW is required. When both CH and HW are on then the boiler fires at the max setting on the control panel (so you don't have rads at 70 degrees). When only CH is on then Opentherm takes care of it and throttles the boiler down as it should. Hope this helps.
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