OV9

We have a combi boiler (I know…) but I do plan to add an unvented electric cylinder to serve half the house when we have had solar installed. So again I can add the hot water control at that point.

I’d be more tempted to have a standard unvented installed, and if the combi isn’t too old remove the hot water elements and use it as a system boiler, you still get an immersion you can add solar control to, without it costing you in winter when there’s shorter days and days with little to no solar gain

Yes, I'd definitely prefer a normal unvented cylinder which feeds the whole house - but in terms of pipework and the boiler location that's probably not feasible. The boiler is an oil-fired external Worcester Greenstar Heatslave 25-32kW combi which as far as I can ascertain can't be converted to a system boiler (unlike the Grant at our old house) and would cost a fortune to replace so that is staying. The house quite neatly splits into two as well, the old bit having a cupboard ideal for a cylinder feeding the kitchen sink, one bathroom and an en-suite, and the existing combi feeding three en-suites and utility room. That gives us resilience if the combi ever fails on a dark winter morning. I might consider getting a normal unvented cylinder but not connecting the boiler feed, just in case we ever did change the boiler. Having two smaller (say 200l) cylinders at different ends of the house is probably the best way to arrange things; can simply not turn one on when the kids aren't around.

No need for a conversion as such, just disconnect the water from it, and take that to the cylinder, then pipe it up as a standard s plan. The boiler will work as is, just with many redundant parts. Bit rough but it works

I think that jeopardises the extended warranty cover but will consider it...

Amazon bumped the price of the Evohome controller/BDR91 up by £20 just as I was deciding to go for Evohome. My wife has said that she finally understood the controller when we moved, so she's happy to have it again. So I've been waiting for Amazon's dynamic pricing to bounce back down or for a Black Friday deal. But nothing yet.

So I had a look at other suppliers and remembered that I got a good deal with my original Evohome installation by buying a bundle. And I have found a pack with the controller, BDR91 and 6 of the simpler radiator valves for £438 delivered, so that's now on its way. The cheapest I'd seen the TRVs in multi-packs worked out as £45 each; if I value them at that, the base controller and BDR91 works out at £168 so this is the best deal I've seen. Buying a pack with more TRVs doesn't work out as well, oddly.

The bigger expense will be getting a plumber in to fit TRV bodies to each radiator that doesn't have one... but I'll worry about that when it's installed. I'm definitely sticking to passive TRVs for the bedrooms to avoid the opening and closing noises.

Jobbo wrote: Thu Sep 26, 2024 9:50 am Amazon bumped the price of the Evohome controller/BDR91 up by £20 just as I was deciding to go for Evohome. My wife has said that she finally understood the controller when we moved, so she's happy to have it again. So I've been waiting for Amazon's dynamic pricing to bounce back down or for a Black Friday deal. But nothing yet.

So I had a look at other suppliers and remembered that I got a good deal with my original Evohome installation by buying a bundle. And I have found a pack with the controller, BDR91 and 6 of the simpler radiator valves for £438 delivered, so that's now on its way. The cheapest I'd seen the TRVs in multi-packs worked out as £45 each; if I value them at that, the base controller and BDR91 works out at £168 so this is the best deal I've seen. Buying a pack with more TRVs doesn't work out as well, oddly.

The bigger expense will be getting a plumber in to fit TRV bodies to each radiator that doesn't have one... but I'll worry about that when it's installed. I'm definitely sticking to passive TRVs for the bedrooms to avoid the opening and closing noises.

How old are the trvs in the bedrooms? Worth considering having them changed at the same time as the others, yes it’ll add expense but will be cheaper whilst drained down than changing them at a later date

If we're changing them I'll probably change the existing ones too - they are probably all 10+ years old.

Is it the valve bodies or the heads which benefit from being replaced as they age?

Jobbo wrote: Thu Sep 26, 2024 11:21 am If we're changing them I'll probably change the existing ones too - they are probably all 10+ years old.

Is it the valve bodies or the heads which benefit from being replaced as they age?

Both. Heads fail with hardening or liquifying wax in them, and the bodies start allowing water past when the head closes- they come as a set anyway

I always recommend new bodies with smart trvs for the passing reason and if they go stiff it makes the heads work harder, at best the batteries don’t last 5 mins and at worst it kills the head

£173.41 in the Amazon Prime deals for the Evohome controller & BDR91.

simon_g wrote: Tue Oct 08, 2024 9:52 am £173.41 in the Amazon Prime deals for the Evohome controller & BDR91.

Spotted that. In the bundle I got it worked out at £150ish but Amazon have reduced the price of the basic Evohome TRVs without a display to £30. So I’m trying to work out how many I want. All the bedroom radiators I’ll keep as dumb TRVs I think.

Google Nest gen 4 controller looks cool…

It’s lovely but there’s no planned uk release as of yet.

Looking cool is a long, long way behind functionality in my priorities

Had an interesting fault pop up on the EvoHome app. Suddenly there was an unknown, unnamed zone with the temp permanently set to 62c showing.

It isn't showing on the controller, only on the web/app. A bit of searching online clarifies that it is a server-side error, a ghost zone that just pops up for some reason, and to contact Support to resolve it.

Oddly on the app I cannot change the temperature, but on the web portal I can. So set the phantom thermostate to 5c.

Using the "contact support" link on the portal leads to a page error, but going via the Irish support link sends you to Resideo where a ticket can be logged.

Update: ghost zones are automatically removed at midnight every day by the system. I guess they got tired of people asking them to help

Can confirm it has gone from ours.

I think one of the thermostats is overreading a tad...



It had run out of battery, no clue why it decided to show that instead of something like a line or a blank tile.

Maybe your piano is on fire. Have you checked?

Simon wrote: Thu May 07, 2026 1:36 pm Maybe your piano is on fire. Have you checked?

He's used an Italian naming regime - its actually a whole floor that's on fire

We are going to need to get a grip (by which I mean automate and zone ideally) of the heating situation at our new place before next winter though I think its going to be a challenge...

It is over 4 floors so currently there seem to be two Honeywell controllers in the boiler room which have three heating zones, 1 being ground/lower ground, another being first floor and another second... I think. Then one side of one controller for hot water but it heats a Megaflow cylinder so we have just set it to "continuous" - no idea if that's ruinously wasteful or what we should be doing as I've only ever had combi boilers before. Ironically we now have a +1hr button for the heating but have to go down two flights of stairs from the bedrooms to put it on.

The old owners also said something about the heating not being effective if you just heat certain floors "because of something to do with a pump". We also seem to have a combination of radiators in some places water underfloor heating in others and electric underfloor in the bathroom but with towel rails that do not seem to be electric but are red hot 24/7 so F knows what is going on there...

British Gas also sent through a closing bill (we've moved to EDF) saying on the basis of last year's usage the gas should be £3,800 p.a.

I can confirm that no part of the house is on fire.

@GG. that's sounds like a right pita to sort out. Would it be worth getting a professional to come go through the whole system?

Remember watching something on YouTube a few years ago with a plumber/heating engineer who was sorting out a substantial property that had a mad setup with two boilers serving different parts of the house.

You could probably spend thousands and untold hours trying to spot fix parts of it, with little or no benefit.