Best option for replacing Honeywell T6360

[MarcelHoldinga]

Hi there!

I've got currently got 6 Honeywell T6360 dial thermostats that were installed as part of water UFH system (Daikin heatpump with DHW cylinder, and the usual manifold with actuators for each loop) and none of them appear to be working right, in that they appear to be set to switch on anywhere between 1 and 3 degrees below the temperature the of the room (i.e. with the room at 21 degrees C, the stat clicks on anywhere between 20 and 18 degrees), meaning they're driving the temperature up, unless I make a mental note of the individual offsets and compensate each room by setting the temperature lower.

I don't have the mental capacity to do this - not because it's not there, but because I CBA to to this...

 

Does anyone have any suggestions for good quality replacements that are not going to cost the earth?

I've had a root around on the internet but there's so much choice and different makes/non-makes that it's kind of making my mind boggle!

 

 

Thanks

Marcel

[ProDave]

I would suggest that they have been wired incorrectly without a neutral connection that is required to power the tiny accelerator heater to overcome the inherent hysteresis with a mechanical thermostat.

 

Any digital thermostat should do as a replacement and solve the problem, but make sure it is suitable for "2 wire" operation.

[MarcelHoldinga]

1 hour ago, ProDave said:

I would suggest that they have been wired incorrectly without a neutral connection that is required to power the tiny accelerator heater to overcome the inherent hysteresis with a mechanical thermostat.

 

Any digital thermostat should do as a replacement and solve the problem, but make sure it is suitable for "2 wire" operation.

 

Thanks ProDave.
The current wiring on the stats is in the attached picture - spoken to the electrician who wired them in yesterday, brown is live, black is the switched wire, grey is neutral and the earth wire is on the left. Does this look right?

When you say 2 wire operation, does that mean that the thermostat is battery operated as far as display and controls goes, with the switching done using the live and switched wires?
I'm not a fan of having to go around replacing batteries - isn't there an option for mains powered thermostats?

 

 

Edited August 4, 2021 by MarcelHoldinga

[ProDave]

What I was suggesting is the neutral may not be connected?  It certainly looks okay.  I would start by getting it checked to see if the neutral is actually connected, if it is there is no reason for the present thermostats not to work properly.

 

Did they ever work properly?  If so they might have failed but that is very unusual.

 

[MarcelHoldinga]

Not sure if neutral is connected at the other side - I can contact the sparky who wired them up to see what he did (or didn't).

They've always been unreliable... I just put it down to inconsistent materials used in making them...

[ProDave]

I am pretty sure these are the thermostats I have, if not a very similar model, they are simple, dependable and reliable, and contrary to popular belief don't have massive hysteresis and control the temperature to a tight tolerance.

 

That's why I wonder if the neutral is connected properly?  If it is not then it affects what you can replace them with.