Replace Honeywell T6360B with Salus RT300RF

[Martyn Bell]

I would like to replace my Honeywell T6360B room thermostat with a Salus RT300RF wireless thermostat.
I would like to fit the Salus thermostat inplace of the Honeywell (fitted to hall wall) in the same location.
The Honeywell has a switched live to control the boiler on pin 3 yellow wire, can anyone please tell me how I should wire this to the Salus?

My boiler is Ideal Logic Heat 18 My programmer is Honeywell ST6400

Can I fit a short link lead from pin3 L to pin2 COM and use pin1 NO for my yellow wire switched live?????

 

[Martyn Bell]

Found a video on the Salus website that shows installation of link lead between terminals 2 & 3

 

[D_Hailsham]

The receiver needs a permanent connection to L and N, not a switched one. The connection to terminal 1 of the Honeywell T6360B is a switched supply, controlled by the CH side of the ST6400.

How many wires in the cable to the T6360B? You need four, as shown in the "Typical Wiring Installation" diagram above.

 

[Martyn Bell]

Thanks D_Hailsham for getting back to me. There are 4 wires to the T6360B Red, Blue, Yellow & Green/Yellow.
Yes it does say that in the manual, but the Salus RT300RF is not a programmer with a clock so I don't see why it needs a permanent connection, otherwise what will happen if there is a power cut?
What do you think?

 

[D_Hailsham]

Thanks D_Hailsham for getting back to me. There are 4 wires to the T6360B Red, Blue, Yellow & Green/Yellow.
Yes it does say that in the manual, but the Salus RT300RF is not a programmer with a clock so I don't see why it needs a permanent connection, otherwise what will happen if there is a power cut?

If the relay box is not fed from a permanent supply, every time the supply is cut, i.e when the timer turns heating off, the relay will stop communicating with the controller. Breaks in communication are not a good idea as this is treated as an error by the thermostat, which then spends all it's time trying to re-establish communication with the relay.

Four wires will be OK. Use red and blue for the L and N connections; and Yellow and Green/Yellow for the COM and NO terminals. These two wires should have red sleeving on them at both ends to show they are voltage carrying wires.

Yes, communication will be lost if there is a power cut, but that's not a regular ocurrance.

 

[Martyn Bell]

If it treats a loss of power as an error & keeps searching for the receiver, I assume this will drain the batteries quickly?
The green/yellow wire is currently an earth which is not needed, but as it is an earth I am reluctant to rewire it as a live. Is it ok to do that?

 

[TCCHeating]

The green/yellow wire is currently an earth which is not needed, but as it is an earth I am reluctant to rewire it as a live. Is it ok to do that?

depends on what type of cable you have. If it is twin and earth style cable then you cannot. As the earth wire is not double insulated. If it is 'round' 4 core flex. And the g/y cable is double insulated. You can use it as a live but it MUST be sleeved with brown sleeving at both its origin and destination.

 

[Echo the husky]

Keep the Honeywell thermostat as a spare for when the Salus goes wrong.

 

[D_Hailsham]

The green/yellow wire is currently an earth which is not needed, but as it is an earth I am reluctant to rewire it as a live. Is it ok to do that?

depends on what type of cable you have. If it is twin and earth style cable then you cannot. As the earth wire is not double insulated. If it is 'round' 4 core flex. And the g/y cable is double insulated. You can use it as a live but it MUST be sleeved with brown sleeving at both its origin and destination.

The Salus relay box does not need to be earthed, so the green/yellow wire is free.

 

[Martyn Bell]

The cable is not round 4 core cable, so I will replace the cable with new round 4 core cable. I can then pick up a permanent supply from terminal 1 on the Sundial Y plan 10 pin connector block which also supplies the ST6400 programmer.
Thank you ounce again D_Hailsham

 

[D_Hailsham]

The cable is not round 4 core cable, so I will replace the cable with new round 4 core cable. I can then pick up a permanent supply from terminal 1 on the Sundial Y plan 10 pin connector block which also supplies the ST6400 programmer.

That's a good idea.

The terminals for the other two wires can be easily identified:

The yellow wire from terminal 3 of the existing stat connects to the white wire from the motorized valve. NO should be connected to the same terminal as the white wire.

You can easily identify the terminal to which the wire from terminal 1 of the thermostat is connected. (Hint: same cable as yellow wire.) COM should be connected to same terminal.

Make sure you disconnect the wires to the old thermostat at both ends and make them safe e.g terminal blocks.

 

[Martyn Bell]

I am still trying to fit the new stat in the same location as the original. I need to replace the existing 3 core + earth as I can not use the earth as a live. Where can I get 4 core cable bearing in mind that it has to run through the loft space. Guess it must be cable not flex. Boiler manual says use 3 core PVC insulated 0.75mm2 (24x0.2mm) to BS 6500 Table 16. Can I run a single live cable to make up the 4 wires needed. Where can I get any cable of this kind?

 

[bernardgreen]

One of many sources

http://www.screwfix.com/p/time-heat-resistant-flexible-cable-3095y-5-core-0-75mm-x-50m-white/20292

5 core but generally more easily avialable in short lengths than 4 core

 

[D_Hailsham]

I am still trying to fit the new stat in the same location as the original. I need to replace the existing 3 core + earth as I can not use the earth as a live.

Any particular reason for fitting the relay box where the existing stat now is? It doesn't have to be there; the temperature sensor is in the contol unit.

You said earlier that the cable to the existing stat had red, yellow, blue and green/yellow wires. Is that correct, or is the earth wire bare? If correct, there's no reason why you can't use the cable provided you put brown sleeving over both ends of the green/yellow wire.

 

[Martyn Bell]

I could fit it in the airing cupboard next to the programmer, but I would prefer to fit it where original is because it is in the middle of my bungalow for good reception also I would't have to fill a hole in the wall.

The earth wire is effectively bare with only a short length of green/yellow sleeving pushed on upto the main grey insulation. How about this cable https://www.tlc-direct.co.uk/Products/CA0dot75F5.html Can I use it in the loft space? I would need about 8 meters