Drayton digistat RF3 installation

[Rob190]

Hi,

Since getting back into the trade a few years back have installed controllers for boilers with room stats etc & the odd new S plan system - infrequently & admit I am not well versed in heating controls though can follow a circuit diagram!

Customer has asked me to install a Drayton digistat RF3 to his current set up on a Vaillant ECOTEC plus boiler feeding an S plan heating & water. This system is currently ran from a Drayton LP722 dual channel controller & has never had a room stat connected - purely on/off via controller.

Current wiring on the backplate is L,N, HW to 3, CH to 4.

Digistat has exactly the same connections but I'm having difficulty getting it to operate correctly - The L & N connections are the same however the manual (and only circuit diagram I can find) shows a switched live to 1 & zone connection to 3.

I obviously don't have a switched live (no stat) & 2 Zones.

The manual does mention linking L & 1 if no separate controller but this just fires the boiler constantly.

I cannot install any additional cables.

So I'm thinking keep the LP722 for hot water & timer for heating, use the timed CH feed for 1 & heating zone 3?

Any help before I go through the tedious process of contacting Drayton tech support would be appreciated.

Thanks

 

[Leesparkykent]

What's the thermostat for? existing CH or for an additional CH zone?

 

[Rob190]

Existing CH Lee

 

[Leesparkykent]

Existing CH Lee

Why have they purchased a programmable thermostat when they already have a programmer to set the times for the CH to come on and off? They would be best off taking it back and purchasing a Drayton Rf601 thermostat.

The receiver needs a permanent live and neutral so this can be picked up from the wiring centre. The greys of the two port valves will be connected to permanent live. CH ON from programmer goes to terminal 1 and terminal 3 connects to the brown of the central heating valve. If they are insistent on using the RF3 then the programmer will have to be set to on for the central heating so they can use the thermostat as a programmer.

IMO it would be best to purchase a normal thermostat such as the Rf601 so the programmer can still be used conventialy to programme the times to come on and off and the thermostat will be just that a thermostat.

The RF3 is more for combi boiler or a separate UFH zone where not controlled by a programmer.

 

[Rob190]

Cheers Lee,

Trying to make it work but stepping back, your comments have clarified my doubts that this wasn't suitable!

Their 'heating engineer' supplied the RF3 & will get it back!

Good to have a heating guru around!

Thanks,

Rob

 

[Leesparkykent]

Cheers Lee,

Trying to make it work but stepping back, your comments have clarified my doubts that this wasn't suitable!

Their 'heating engineer' supplied the RF3 & will get it back!

Good to have a heating guru around!

Thanks,

Rob

Yeah it would be best IMO. It looks a bit bodgy to me when there is a programmer and a programmable thermostat in series. Quick look and the thermostat I mentioned is only about £5 more. http://www.screwfix.com/p/drayton-digistat-rf-room-thermostat/73146