Google Nest with new tank stat (Drayton HTS3)

[JustYourAvgJoe]

Good morning everyone. I recently installed a Nest 3rd Gen to my system. Everything was working perfectly with a old and brittle Drayton HTS3. I purchased a new Drayton HTS3 installed it and everything stopped working. I previously had the stat set to 60degrees so I put this one the same and nothing. Even with a schedule or using ‘boost’... nothing

Now here’s the weird part, well for me anyway... if I turn the stat all the way down/turn off. It works! The minute you go above 40-45 it clicks off. It seems to be working in reverse. Once again, the old one worked flawlessly. I imagine it was installed with the house back in 2003

Can anyone please help?! If I click the button in the Heatlink, it goes into manual mode so it must be a problem with the stat? I’ve bought two and they’ve both had the same results

Thank you

 

[CBW]

Sounds like it’s wired back to front? Any photos of wiring at Nest and Drayton?

 

[JustYourAvgJoe]

Sounds like it’s wired back to front? Any photos of wiring at Nest and Drayton?

That’s what we thought, when we demand it’s satisfied and when it’s satisfied it demands... I can get some pictures tonight when I’m home. It’s strange because the previous model was wired the same and it worked. We switched the demand and satisfied wires over and it come up with an error on the Nest....

 

[ianmcd]

What system do you have ? S orY plan ?

 

[JustYourAvgJoe]

What system do you have ? S orY plan ?

From memory I’m not too sure. When I get home I will check and report back on here

 

[JustYourAvgJoe]

Morning guys. We had a look last night and I have a Y plan. We swapped over the supply and demand cable and weirdly it worked!! I say weirdly because we did this exact process on the day we was having the issue and it come up on the Nest as an error. A guy called Steve at Drayton was very helpful in running through the process with my dad just to make sure we had the cable in the right connections, so a shout out to Steve!

Thank you for the responses yesterday, it was much appreciated