Wiring a new room thermostat Ask questions and find answers to many subjects relating to electrics and electrical work

[jm2000]

Hi, i have a Ravenheat csi 120 (t) low nox combi boiler but there is no room thermostat so i have bought a Salus wirless digital thermostat with RF (RT 300rf).

My problem is the instrucions for wiring are simple enough but i am unsure of which wires in the boiler to use.

On the main board in the boiler, there is a room thermostat block with 2 points which have a 1 wire loop.

on the thermostat there are 5 points SL(off), live in, SL (on) Neutral and live, both lives are linked.

Please could someone help, i have had my cousin (an electrician) around but he has not done one, but did explain how i should do it...but i am still confused....he did check with a meter on the points in the boiler and said it could be volt free.

Please help me....i am usually ok with things like this but this has me stumped. :(

[ericmark]

If the Salus wirless digital thermostat with RF (RT 300rf) is volt free then likely you will have two cables going into it one giving it supply and the other connecting it to the boiler But you say your cousin (an electrician) says boiler is volt free that does not make sense. Having gone to the Salus web site I am not surprised as it seems they have printed errors. So since I don't know volts of boiler I would connect the two terminals that had link wire in on boiler to L in Com and LS (on) NO and connect the N and L to live and neutral either in boiler or second plug and I would not fit the bridge wire shown in their diagram between L in Com and L as if your boiler is 24 volt fitting this wire could one be dangerous and two do damage. Since I can only go by the very bad Salus web site I would get an electrician on site to test and wire as there could be other errors and to be safe really needs someone on site to check. Also the Salus unit does not look like an outdoor model and I would expect you have TRV in each room with such a new boiler so no point in doors I would be careful where you mount the sensor part of unit. I think your boiler control is 230 volt and C on boiler is 230 volts and D is run but in case I have looked at wrong diagram on web site you really do need to check on the paperwork that came with the boiler.

[jm2000]

Does it matter which way these are wired as we have done this, and the wireless thermostat is asking for heat (set at 35oC And house is 22oC) and the boiler fires up every so often for no longer than a second. the pump is running, and the hot water works.

[ericmark]

Looking at web site info as long as C,D connects to Com LS(on)NO and no links between these and L and N then should work. But since it can be seen there are mistakes I would try Com and LS(off)NC instead the problem is what condition is considered as normal. Correct way around is C to Com then D will be one of the LS terminals. Also N to N and either L to L or link L and Com but not both. The two radio units must talk to each other but even if they don't trying the two LS terminals one should run boiler even if it will not turn off. You need to go onto frequently asked questions then select your thermostat I think the diagram for your boiler which is 230 volt control is correct but the diagram for 24 volt boiler is up the creak.