The Efficient Home Forum

Hi all,

First time post on here.

I've had Evohome for about 3 years now, but am about to extend the system from 8 -> 10 HR92s (all rads) and change from a y-plan to an s-plan as part of a new boiler installation.

I will configure the upgraded system as per figure 4 in the Evohome installation guide, with the heating zone valve locked open, one BDR91 acting as DHW relay and the other as a remote Boiler relay. I will clear and rebind as part of this upgrade.

My major concern is that the new boiler my trusted installer is suggesting to install is a Baxi EcoBlue Advance Heat only, and this model is not wired with a permanent live and has no pump override feature. Are there any downsides to not having a boiler pump overrun when using Evohome?

Are there any complete wiring diagrams for figure 4 available?

Thanks in advance for your help,

Dave

Hi Dave,

If the boiler manufacturer does not require pump overrun, then that is the choice of the manufacturer and it does not affect the evohome system.

There is no Honeywell diagram of a figure 4 wiring setup, apart from the one we supply to our customers in the customer only area of this forum.

Kind regards,

Richard

Hi Richard,

Thanks for your info.

Actually, I'm now on the verge of changing to an Intergas Compact HRE 24 OV, which my installer is also happy to fit for me.

Then I will probably but the newer WiFi Evohome with an Opentherm Bridge later in the year.

Thoughts?

Dave

Hi Dave,

The Intergas boilers are great bits of kit and certainly the most advanced OpenTherm boilers out there... Hence we exclusively sell them on https://theintergasshop.co.uk

Any of the Intergas range is capable of being an Open Vent (OV) boiler, which is a great USP for Intergas... So you can have an Intergas ECO RF 24 with a 10 year warranty as an OV boiler just by changing one parameter. In this situation you don't connect the DHW hot and cold pipes, disconnect the pressure sensor and tee the PRV into the return... Easy stuff!

This is a little overview I did with evohome an our ECO RF 24 boiler - https://theevohomeshop.co.uk/content/21 ... me-with-it

I hope that helps, but if you need any further info let me know!

Thanks,

Richard