Installing 3rd Gen Nest in Glow-Worm Ultracom 2 35 Store

16 Nov 2023
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United Kingdom

I'm looking to upgrade the wireless thermostat system used on my Glow-Worm Ultracom 2 35 Store from a Climapro2 to a 3rd Generation Nest I've recently purchased. I had hoped I'd be able to hook into a couple of screw terminals on the 24V board (after getting 240V from the junction box powering the boiler), however the Climapro2 RF unit hooks into an HBus and the other terminals don't look like these are screw terminals on the sockets connecting into the plugs on the main board. Has anyone managed to hook a Nest into an Ultracom 2 35 Store previously, I've read a few articles (Closest match I saw was here) on here for different Glow-Worm boilers but these didn't seem to be similar to the one I'm trying to connect? Any advice on this would be greatly appreciated, I've attached some photos of the connectors I'm working with.


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Closest match I saw was here
Just as in that post,
You can't connect the Nest to the ebus terminals. It needs to go to the 24v and 0v terminals
How about these ones...

However, using Nest on these will restrict the efficiency of the boiler. The control will be on and off, whereas the ebus allows finer control of the boiler and it's modulation.
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Thanks for the reply. Point taken about the finer control loss I might get with the current Climapro2. I'll try connecting the Nest and disconnecting the Hbus. If it seems the Nest isn't as good I'll revert back to the Climapro2.

Thanks again @RandomGrinch
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You need to be very carefull wiring that to a nest, you will seemany posts on here and elsewhere, saying to link L&2&5 DO NOT do that with your boiler or it will be a very expensive nest that you fitted

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