Thermostat replacement

[richardhowell]

I moved into my new house recently to find the downstairs underfloor heating temp (gas boiler, not electric) is controlled by four “nightmare” thermostats in lounge, kitchen, hall and utility room. (See photo). I've had several attempts to program them, but can't get my head around setting temperatures for the SEVEN different time zones plus all the other variables I need to consider. They are just far too sophisticated for my requirements.


So I want to replace them all with simple dial-controlled stats in each of the rooms.


Questions:


(a) Can they simply be replaced with "ordinary" stats, or does underfloor heating make it more complex?


(b) Is it a DIY job or should I get a qualified electrician?

 

[ericmark]

In the main wet underfloor heating has the max water temperature controlled by a thermostat on the manifold, so any wall thermostat will do.

But it depends on the manifold, there may be some where they do use under floor sensors.

 

[RandomGrinch]

It's difficult to tell from one picture, what system you actually have - Google suggests it may be part of the Salus iT600 system:

If it is, the system is quite complex, and could include a manifold, receivers and underfloor sensors.
Replacements with simple dial 'stats may not be simple.

On the other hand, it is possible that your system has an App, and this could hugely simplify the programming of the separate thermostats.

I'm afraid you may need to do some more investigations to find exactly what system and components you have.
And when you have that information, a post on the "Plumbing and Central Heating" forum may be beneficial.

 

[richardhowell]

The stats are Speedfit Aura, if that helps.
Thanks for your replies. I'll do a post on the plumbing forum as well to see what they say.

 

[RandomGrinch]

The stats are Speedfit Aura, if that helps.

Yes, that's the same system as I linked to - just a different name.
Apparently they are wireless thermostats, and possibly have connections to floor sensors - they are not a straight swap with dial 'stats.

Manual attached.

 

[richardhowell]

I took the front cover off and googled JGSTAT2W/B and it seems like it's a wired stat

 

[RandomGrinch]

I took the front cover off and googled JGSTAT2W/B and it seems like it's a wired stat

Ok, that's slightly easier then.
Link to the manual:

SPEEDFIT JGSTAT2W INSTRUCTION MANUAL Pdf Download

View and Download Speedfit JGSTAT2W instruction manual online. 230v Thermostat. JGSTAT2W thermostat pdf manual download. Also for: Jgstat2b.

www.manualslib.com

Can you see what wires you have connected? There could be communication wires and sensor wires..

If you have the communication wires, the 4 stats can be set as a group, which would make programming more straightforward.

Alternatively, the JG dial thermostat would be a suitable replacement:

JG Speedfit JGSTAT1 Aura Dial Thermostat 230V | Toolstation

Can be set to 3 temperature variations (automatic, manual and frost). Dial thermostats can be part of a group or operate on their own.

www.toolstation.com

It has both the communication terminals and the sensor terminals, that a more standard 'stat wouldn't.

Manual attached.

 

[richardhowell]

Here's the wiring - black brown and grey. Looks simple!

 

[RandomGrinch]

Here's the wiring - black brown and grey. Looks simple!

Good!
It would appear grey is neutral, brown is live and black is switched live - at least on this thermostat! (Check the markings when you take the stat off).

Now find yourself a simple dial 'stat!

Sorry if I wasn't clear, but when I said...

I'm afraid you may need to do some more investigations to find exactly what system and components you have.

I meant tell us what components you have, how it is wired up and give us pictures!
It does make it far easier for us, to help you!

 

[richardhowell]

You've been very helpful indeed, RG! Thank you.
Just one more question - are the stats on my downstairs ring main or lighting circuit (for isolation)?

 

[RandomGrinch]

You've been very helpful indeed, RG! Thank you.
Just one more question - are the stats on my downstairs ring main or lighting circuit (for isolation)?

Now wait a second, while I get my crystal ball!

The 'stats are unlikely to be on a lighting circuit.

It is usually best practice for heating controls to be on the same circuit as your boiler (and may even turn off when you switch off the boiler FCU).
Also, in this case, everything is likely to be connected back to your manifold controller.
If there are any indicator lights on the controller, they should extinguish without power.
However, before attempting any disconnection, the circuits should really be tested, to confirm they are dead. A multimeter may be an invaluable investment, for under £10.

 

[EFLImpudence]

are the stats on my downstairs ring main or lighting circuit (for isolation)?

Probably.

 

[richardhowell]

A bit like Schrödinger's cat. Either or both circuits could be alive or dead at the same time ??