help please replacing a drayton with a Horstmann DRT2

[pho]

hi,
I am trying to replace my old Thermostat acl Drayton with a Horstmann DRT" but there are 4 wires in the old thermostat and I am not sure which to use.
Inside the Drayton it says T45, and there are 3 wires connected - Blue to N, Red to L and Yellow to 3 (call), now the drt2 has 3 connections com, nc and no, any idea which wire goes in which connection?

many thanks

 

[Roo]

Sounds like your replacing a mains powered thermostat with a battery powered one?

Com = Common
NO = Normally Open
NC = Normally Closed.

Only based on how your previous stat is wired.

Blue = Neutral, on New stat not used.
Red = Live, On new stat is Com
Yellow = Switched Live, On new stat would be NO.

Any earth wires should be connected to the relevant earth terminals.
The neutral should be properly terminated so it can not come into contact with any of the lives.
I would use a choc block or similar.

The above is how I would wire it and I'm not a plumber and know nothing about Boilers.

 

[pho]

yes it is a mains one currently, so the earth and the Neutral just need terminating ?

 

[Roo]

yes it is a mains one currently, so the earth and the Neutral just need terminating ?

The earths need to be terminated at the earth terminal.
Usually a metal screw in the back plate somewhere.

The neutral needs to be insulated in a way it can not come into contact with anything (ie a choc block).
Don't leave the neutral exposed or dangling about as when you screw your stat to the wall there's a chance it'll come into contact with the lives.

Whether your boiler needs a mains powered stat I've no Idea as I've said I know nothing about boilers.

 

[pho]

ok thanks, Anyone out there know if I have to replace a mains thermostat with a mains one? or does the boiler just need to make or break a connection to fire?

 

[Roo]

What is the exact model of your current stat?
After just reading on the drayton site it seems that some switch the Neutral in which case what I have told you would be wrong.

 

[pho]

the only info I have on the old one is ACL Drayton on the outside and T45 on the inside

 

[Roo]

the only info I have on the old one is ACL Drayton on the outside and T45 on the inside

A quick google and it seems T45 does switch the live so Wire as I first wrote.

Sorry for the confusion.

 

[pho]

OK thanks