Help fitting Excelvan BYC17.GH3 room thermostat

[Tony107]

Can anyone help with a connection issue i have changing my old Drayton Type RTC room stat to a Excelvan BYC17.GH3 Programmable Heating Thermostat.


On the Old Drayton I have 2 cables coming one with a red and an earth wire and the other with a red, earth, Blue and a yellow wire.

Earths go to an earth conection.
Red to N
Red to Line
Blue to Cooling
Yellow to Heating

Connections on new Excelvan stat
AC 230v L & N
Load L1 and N1

On some simple testing I have a live from a lighting mains, the red that is connected to N(neutral) tests as live 240v on simple screwdriver tester.
The N red and Heating yellow test for 240v on a multimeter.

Any help much appreciated.

Tony

 

[ban-all-sheds]

1) Unless that screwdriver is a good screwdriver, throw it away, as it is a useless-to-the-point-of-dangerous electrical tester.

2) There may be a terminal marked N, but does the RTC use neutral to function? It might have volt-free terminals, so if there is no neutral present then your new one won't work.

 

[Tony107]

1) No its not a good screwdriver so throwing away now.

2) This is what i do not know and what I need to determine.

Thanks ban-all-sheds

 

[Echo the husky]

If your existing wiring needs a normally closed connection (marked as cooling on your old stat) then this new thermostat is not compatible.

 

[ericmark]

It seems strange to fit an underfloor heating thermostat to replace a standard thermostat, have you got under floor heating? Also seems to be too many wires, you need to tell us more about what you have.

 

[Tony107]

No I dont have underfloor heating. Its not a dedicated floor heating stat its an optional sensor and setting. The default setting is to measure air temp.

So the old stat is a 20 year + Drayton RTC. We had the main programmer changed fron an old Danfoss Randell 4033 programmer to a Honeywell ST9400C when we had the bathroom fitted and some new rad stats some months ago but at the time hadn't decided on which room stat to buy.

(would have been a lot easier I know but having done many wiring installs allbe it not heating wiring its a job I thought would have been a lot simplier, which seems to be the case with most jobs in this new place of ours) Anyway I digress

The programmer controls a Thermecon Option Oil Boiler heating hot water and Rads.

Thanx

 

[Tony107]

If your existing wiring needs a normally closed connection (marked as cooling on your old stat) then this new thermostat is not compatible.

If this is the case could it not be rewirred at the programmer/boiler end?

 

[EFLImpudence]

Perhaps.

Give us a wiring diagram of the system.