Thermostat Advice

[bagstone]

So, been putting this off for a while due to choice paralysis. Got a ProCombi 30 Exclusive boiler with a Salus RT500RF. Programming that requires 5 minute of cumbersome button smashing. Want something more modern:

• Something easier to program/re-program for our schedules.
• Ability to turn on/off via app (also remotely, if not at home)
• Potentially add smart TRVs to the radiators

At the moment, my front runner is Drayton Wiser. It sounds like it's a bit more reliable and versatile than the other options. I'm thinking this one here, Black Friday sale.

My local plumber doesn't know Drayton (nor Tado, the other option I was considering), so I was wondering if anyone here knows if that would work for our system?

Especially, the towel drying radiator in the bathroom doesn't have any TRV right now, could we fit a Drayton smart TRV on there? Pic below.

 

[stem]

From a wiring point of view, the Salus receiver is replaced with the Wiser One Channel receiver (the version for Combi's) that comes with the Wiser.

WISER

SALUS

Provided that your Salus and new Wiser conform to the above, the wires transfer as below:

Salus 1 NO = Wiser 3 ON
Salus 2 COM = Wiser 1 COM
Salus 3 L = Wiser L
Salus 4 N = Wiser N

If there is presently a link wire between the Salus L and COM terminals, then also link the Wiser L and COM. Note: Do not add the link if it does not currently exist at the Salus.

The TRV's can be fitted where required. But should not be in the same room as the main control thermostat, this is because one will interfere with the operation of the other.

I don't think it's likely for you, but some systems require at least one radiator not be fitted with a TRV to ensure a flow of water through the system when the other TRV's are closing, and often it is the towel radiator, your local plumber should be able to confirm.

 

[bagstone]

Cheers, thank you very much! Do you think this is a DIY job (fitting the thermostat, not the TRV obviously)? I have no rush installing the TRVs, but the plumber is only coming around on the 19th for something else, and I don't want to have the thing lying around for that long... plus if he has no experience fitting it, I might as well myself - especially given your excellent instructions. Also currently asking my usual sparky if he knows Drayton/can fit it... I'm comfy with electrics as long as I know 100% what the wires do and there's no certificate needed. But I guess a sparky wouldn't change too much either to fit this...

And yeah I don't plan on replacing all TRVs, probably only bathroom/office for now, and the one in the kitchen (where the boiler is) would probably stay "non-smart" even if I was to replace the remaining 3.

As for the connections, here's what the connections on the Salus look like right now.

 

[stem]

If you are able to terminate the wires safely then it's fairly straight forward swap for DIY. Just move the four wires from the Salus to the Wiser terminals that have the same function, as per my first post.

Don't make the link between Wiser L and 1 COM that's shown 'dotted' on the Wiser wiring diagram.

The other joined wires stay as they are. I'm assuming they are properly connected in some sort of terminal under the insulation tape.

 

[bagstone]

I don't think there's a terminal under the wire, they're just twisted together and connected. It's just the ground wires as you can see by the colours.

 

[ericmark]

This thread just as I was thinking burr its cold, need to heat the living room. So little difference between comfortable and cold, one thermostat 1ºC from turning on the central heating, the other just 0.5ºC from turning on with the schedule set.

I see the whole idea of a thermostat, which will turn on heating before I feel cold, this room one radiator the TRV says 19ºC heating to 24ºC which it is not doing as boiler not running, the other 19.3ºC heating to 21ºC again not doing a thing since boiler not running, And not helped as can't remember the login for the wall thermostat.

Lucky google home still working so can up the main thermostat setting. It also shows so I can set TRV's and wall thermostat in the same app, But this is the problem, we all want an automated system, but half the time it does not work. OK, age 73 does not help, maybe if younger I could remember the pass words?

But does not change the fact that the more items there are able to turn on heating, the better. So yes, like the idea of Wiser (wish I could remember the log in) as once I fit more units (TRV heads) it will better control the house. Lucky I can manually turn the thermostat up.