Wiring a Drayton HTS3

[Johnny Thunder]

I have a 3 port valve ,traditional gravity fed system .And a hive system
I,v wired a exact replacement dragon hts3
Earth to call for heat
Blue to satisfied
Brown to common
As before ,
Question one -Is this right ?
Also
When I put hot water only On Heating also comes on .

 

[ChrisJP]

Hmm - that existing wiring looks suspect.
Brown should be the live feed - to both the thermostatic switch and, if fitted, to power the heater on a by-metallic strip thermostat or to power the display in an electronic thermostat if this is not battery powered.
Blue should be the common neutral needed for a mains powered thermostat but not for a battery powered one.
There should then be a switched live and it appears on your wiring that the earth conductor has been used for this. That will work, but is bad practice - 3 core and earth cable should have been used so that the earth conductor could not become live under any circumstances.

 

[Johnny Thunder]

It's not battery powered.
So ,blue to C
Brown to 1
Black to 2
Earth not used.
So if i Trace my earth cable from the thermostat back to my honeywell power head v4073a mid position valve box (it should not be connected to any thing ,and the black should be connected to grey

 

[Johnny Thunder]

 

[Johnny Thunder]

 

[ChrisJP]

Ahh..you didn't mention the black wire in your initial post! So 3 core plus earth wire WAS used.
However, in both pictures, the black wire appears to have been cut off next to the outer sheath, thus defeating the purpose of 3 core and earth, and forcing the use of the earth wire for a live feed. I've no idea why this was done.
The wire attachments in the second picture look dodgy also - they should be wrapped around under the screws.

 

[Johnny Thunder]

No ,there was no black cable .
But if i replace a with a 3 core and earth ,would it go like this ....
blue to C
Brown to 1
Black to 2
Earth not used.
So if i Trace my earth cable from the thermostat back to my honeywell power head v4073a mid position valve box (it should not be connected to any thing ,and the black should be connected to grey ?would that be correct?

 

[RandomGrinch]

I'm afraid there is some miscommunication here...

that existing wiring looks suspect.
Brown should be the live feed - to both the thermostatic switch and, if fitted, to power the heater on a by-metallic strip thermostat or to power the display in an electronic thermostat if this is not battery powered.
Blue should be the common neutral needed for a mains powered thermostat but not for a battery powered one.
There should then be a switched live and it appears on your wiring that the earth conductor has been used for this.

Although generally true for a room thermostat, the OP has changed the Drayton HTS3.
This is a tank thermostat, it does not have a neutral, but does have Common, Normally Open (NO) and Normally closed (NC) terminals.

traditional gravity fed system

You call it a traditional gravity fed system, yet having a 3 port valves suggests you have a fully pumped 'Y' plan system.

Regarding the wiring, the old stat had Brown to Common, Blue to NC and Green/Yellow to NO.
This appears to have been connected correctly to the new tank stat...

Satisfied = NC
Call for heat = NO

So, it should work, if the old system was working correctly. What made you change the tank stat?

No ,there was no black cable

There is no black 'Cable', but there does appear to be another core (a black wire), within the existing cable. This has been cut short, but could be reinstated if there is enough slack in the cable.
You would simply swap the green/yellow wire connections, for the black wire.
For the sake of the regs, the black wire and the blue wire should be oversleeved in brown to denote them both as switched lives.
However, for the sake of troubleshooting, leave them as they are for now!

 

[Johnny Thunder]

When I turn on just water ,heating comes on ,as I'd changed the honeywell power head last year ,I suspected the tank thermostat .
Yes sorry its a y plan

 

[RandomGrinch]

When I turn on just water ,heating comes on ,as I'd changed the honeywell power head last year ,I suspected the tank thermostat .
Yes sorry its a y plan

That sounds like it may be a passing valve, rather than an electrical issue.
Without the power head on, can you exercise the valve manually and see if that helps?

 

[Johnny Thunder]

I can turn the valve about 33 degrees by hand