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Cannot Pair Salus RT305TX with RXRT505 Receiver on Vokera 29A Boiler

Postby saki » Fri Jan 20, 2017 2:23 pm

Vokera 29A boiler was operating with no problems with Salus Transmitter and Receiver detailed above. The transmitter was powered by two AA batteries supplied by manufacturer. Appears they were poor quality and leaked when I was on holiday. I bought new transmitter but now cannot get it to pair with the receiver. I am trying to pair with transmitter in same room as receiver to eliminate obstructions etc.

Two issues.

Four wires in receiver. Brown and blue to L and N. Grey and Black to NO and COM. (connect to boiler external loop). Is Grey to NO correct? Or does it even matter?

Manuals suggest that DIP switches in receiver labelled 1-5 should correspond to jumpers in transmitter. Currently 1&5 in receiver are set to OFF. Do I remove jumpers in position 1&5 in transmitter to correspond?

Both receiver and transmitter manuals suggest that further details are available if pairing proves a problem and each refers to a page in the other for these further details. So in fact no further details are available! Is there a better setting to improve chances of pairing ie 1 to 5 all ON? or any further suggestions to improve chance of pairing.

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Postby ericmark » Fri Jan 20, 2017 10:22 pm

I can't really answer question, but I can tell you what happened to me, this may help.

I had a Horstmann HRFS1 programmable thermostat, when I bought it found you could use as free standing, however there is no indicator to say how good the RF link is, and if the link is lost it continues to do whatever it was doing, so either no heating or house is roasting.

So I screwed to the wall, worked for a time and then started to stop working again, swapped batteries just in case, and remounted being very careful there was only one wall between transmitter and receiver.

It still played up so moved dip switch and removed one link, nothing, tried the dip switch other end of row of 4 and it worked. It failed again, moved next dip switch and removed another link.

It failed again, moved into room with boiler.

What I did find is once it has failed you have to move it other side of set point and back again for it to work again, maybe in time it does resend, but must be a long time. Also on moving dip switches and removing links the re-set has to be pressed which was a real pain as all setting are lost.

Also have a Honeywell Y6630D wireless thermostat and a programmer to go with it, idea was at night use Honeywell mounted in mothers room, and day use Horstmann mounted in living room, it did work to start with, but come to the conclusion the Horstmann is faulty.

I wanted different temperatures Wednesday and Saturday so wanted 7 day programming, there are not many that do 7 day.

So I needed to get some sort of replacement, I decided to go for MiHome eTRV's in the two down stairs rooms, I also wanted to be able to set and cancel an alarm from down stairs, and if possible outside the house, the MiHome RF socket would allow this, so killing two birds with one stone.

Setting up the eTRV's was a problem, I had wrong spacer fitted, and also had not fully retracted the pin before fitting, also had to move the Honeywell to hall. It now seems to be working A1, just some tweaks on the times and temperatures. It seems the MiHome eTRV heads will pair with the Nest thermostat, I may get Nest in the future, but for time being just got the eTRV's they are not cheap.

There is another system called Evohome which does similar thing, the eTRV's tell central hub when heat is required then central hub tells boiler, if anything better than what I now have.

I can now alter the room temperature anywhere that I have phone reception, however it was not done to be able to do that, it seems I can set it to turn on heating as I get near home, if I enter the locations in the system.

I think Hive also has extras as well as thermostat, which is the best or cheapest I don't know.

If the Horstmann had stopped working totally that would have been good, you know you need a new one, but this working one day then not the next, then starting to work again I hunted for external problems, told even the fan in the boiler running can upset the thermostat. Which has gone faulty I don't know? receiver to transmitter.

I think the eTRV has info sent to it, when to change temperature and what temperature to change to, but it then stores that info in the valve, so any local interference will not stop it working, but not sure on this.
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Postby saki » Sun Jan 22, 2017 3:19 pm

Hi Eric,

Thanks for your reply. It inspired me to tinker with receiver settings. Changed all dip switches to ON and left all 5 jumpers in on transmitter and that did the trick. Now all working fine.

Perhaps the settings on receiver have to be changed if the pairing is lost?

Similar to my bluetooth keyboard. If the pairing with PC receiver USB stick is lost I have to move the receiver to a different USB socket to get it to pair again.

Anyway just glad it is back working again.
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