The Efficient Home Forum

I beleive that I have an S Plan Configuration, but still a bit unsure!

Just in the process of setting up the Evohome.

My existing (old) system is as follows:

I have a Worcester Bosch GREENSTAR UTILITY 18/25 Oil Boiler
This is currently controlled via a Heatmiser PRT/HW-WTS Thermostat (with a Heatmiser RC1-WTS wireless receiver)
There is also a Honeywell T6360B1028 wall thermostat in the mix – only because this was already in place prior to the Heatmiser ‘upgrade’ (this is always set to 30 degrees, so always 'on')
There is a Honeywell T4360A1009 FrostStat near to the boiler
I have a Range Tribune HE Indirect 210L cylinder (unvented?)
I believe that the plumbing is connected in an S-Plan (their are two, two-port zone valves - one for Heating and one for Hot Water?)

I've purchased an Evohome system (ATC928G3000), with 8 x HR92 & 4 x HR91 wireless thermostats, a BDR91 for Heating, and then the Hot Water Kit. I've also got the Wall Mount.

Firstly, can I just relace the existing wall thermostat with the Wall Mount (by simply connecting the two Neutral lines together)?

On to the Boiler Controls - I've read a lot about essentially 'cutting out' the Heating Zone Valve entirely - so the Heating is always on (if the Boiler is on) and running round the radiator circuit, being controlled at each radiator by the HR92/HR91's. Is this correct?

Any other thoughts, observations, learnings would be hugely appreciated.

Many thanks

Do you have a G3 related qualification for the works you will need to do on your unvented cylinder and the competency to test the electrical system once you have modified it?

evohome is a complex system that should be fitted by a competent person. At least get someone to wire the 'bits' you don't know about and then program and configure the evohome system with support from Resideo's technical support?

We recently had someone who blew up their BDR91T because they didn't know how to wire it correctly. It was £100 for them to replace it, which would have probably been a similar cost for a competent person to have come and done it in the first instance.

Not teaching people to suck eggs, but evohome isn't a DIY system imho.

All good points.

My excellent, qualified plumber isn't free for a couple of weeks....so I'm mainly trying to pre-check that I've got everything ready for when he turns up.

Reason is that I had a disaster earlier in the year with Worcester Bosch - as they had misled me completely, and I needed to go back and buy additional bits again and again - which meant that my plumber had to keep coming back...leading to increased costs and epic amounts of wasted time. From that experience, we identified that my existing system wasn't installed correctly, so a number of 'enhancements' have had to be made to ((sort of) make it compatible with upgrading to a Smart system.

Villageidiot wrote:Reason is that I had a disaster earlier in the year with Worcester Bosch - as they had misled me completely, and I needed to go back and buy additional bits again and again - which meant that my plumber had to keep coming back...leading to increased costs and epic amounts of wasted time. From that experience, we identified that my existing system wasn't installed correctly, so a number of 'enhancements' have had to be made to ((sort of) make it compatible with upgrading to a Smart system.

Yep I hear you. Really important to get an installer who has lots of experience of evohome and a fixed quotation, rather than an estimate.

Cheers - much appreciated.