RF thermostat receiver turning on then off again

[PrivateMoment]

I have a Baxi 124 combi boiler with a Flomasta RF thermostat fitted. The boiler is still working fine for hot water, but when the thermostat signals for central heating the green light on the receiver shows but then immediately goes off again (twice, before apparently giving up).

Is there anything obvious (and hopefully home-fixable) that may be the problem? Can't seem to find anything in a search...

 

[ericmark]

I had a wireless go wrong, and it happened slowly is got less and less sensitive temp cure was to bring the wireless part closer and closer to the hard wired bit.

 

[PrivateMoment]

Well, before I posted the above I power cycled the boiler, the thermostat, replaced the batteries and tested about a half dozen times and it kept happening...but after posting it I went downstairs and two minutes later the boiler came on just fine No idea what caused it or what resolved it which is obviously a bit worrying so if anyone does have a suggestion just in case it happens again that'd be grand but for now the issue is resolved.

@ericmark thanks for that, it seemed like the receiver was getting the signal, it seemed to be more that it was resetting or cancelling each time it received it - the green light came on with an audible click of the relay but then went straight off again.

 

[ericmark]

No radio hams live near to you? As a ham I am permitted except when near to houses or parliament to use 400 watt on 70 cm which is same band that many thermostats use with mW output, OK most hams will not use anywhere near max permitted on that band, tends to be mobile use, but because a shared band, it is possible some thing else is using the same frequency which stops it working every so often.

The important thing is to fail safe, i.e. off, which yours did, one I had simply did not change, so if on heat, it continued to heat.

It really was not too much of a problem, as TRV's on every radiator so really the wall thermostat does nothing. I fitted a second in parallel as neither were in a good location, so one in kitchen and one in hall, this allowed for change in wind direction or morning and evening sun to over heat either the hall or kitchen without turning boiler off, all the wall thermostats were for is to stop boiler cycling in warm weather.

 

[bernardgreen]

but because a shared band, it is possible some thing else is using the same frequency which stops it working every so often.

433.92 MHz is shared by other wireless heating systems controllers, wireless burglar alarms, wireless door bells and a variety of other types of equipment. Not all the equipment on sale complies with the regulations.

 

[ianmcd]

It could be that a neighbour has the same thermostat and it is interferring with your receiver, they all come set on the same frequency so change your frequency settings settings it is very easy to do

 

[ericmark]

It could be that a neighbour has the same thermostat and it is interferring with your receiver, they all come set on the same frequency so change your frequency settings settings it is very easy to do

I looked at that on mothers, you can change the code, which is a tone to tell the receiver this signal is designed for you, but not the frequency.

 

[bernardgreen]

you can change the code, which is a tone to tell the receiver this signal is designed for you,

Most often it is a digital address prefixed on every message that can be changed, but this does not ensure the receiver can hear the message.

It is like a couple of people having a conversation across an otherwise empty room. Easy to converse, but then a crowd of other couples come into the room and start have conversations. A conversation where the couple are standing side by side tends to work, but when the couple are separated by a few feet their conversation is going to be disrupted. Enter a person speaking very loudly and then most conversations are disrupted. (*)

(*) this is the illegal equipment transmitting RF power above the maximum permitted power and/or exceeding the time constraints

 

[ericmark]

With packet radio it was a case here is a massage x long have you got it, and a reply either no missed that or yes that was OK, but with a cheap wireless thermostat no reply is send, so all it does is send on change and cross its fingers it was received, some receivers want a message every ½ hour and it no message turn off, and the message is repeated every 20 minutes even if no charge, but unless two way coms, it is a little hit and miss. Be it a tone or an address the same problem, if it does not get the message, it does not know it needs to resend.

And we have all sorts today using wireless, from the door bell to the TRV. I have looked at the frequency used and tired to find it, with hope once found signal could also find anything blocking signal, but have failed.

I remember on prospective ham being hassled by next door for causing interference, we were doing the RAE together and I know he was being a good little boy and not transmitting until he had his licence, but next door was adamant he was causing the problem, then we found a visitor who had illegal CB in his car, was finishing off his chat sitting outside his house before coming to door and ringing door bell.

Be it a taxi, ambulance or police there are people who can transmit with a lot of power, years ago before digital the house across the road to dads was a police house, and the police car radio would come through my dads electronic organ.

And we have pointed out many times, 12 volt lights are designed to have short leads and tungsten bulbs, if some one has longer than recommended leads and fits LED bulbs we have no idea what it will transmit.

I decided hear to use a wired thermostat, it still sends frequency coded massages, same as a LAN, but as with a LAN through wires which also power it.

However it may have been a one off never to happen again. So only time will tell.

 

[PrivateMoment]

Well, the problem's gotten steadily worse and today I've cycled it a dozen times and it does the same thing - goes on then immediately off again. I have changed the channel on the transmitter and receiver, and brought the transmitter right up close to the receiver; neither works. I think it's very unlikely to be interference from somewhere given that it's unaffected by proximity and completely consistent. Any further suggestions?

 

[Madrab]

If it's less than a year old then it's still under guarantee, take it back and get a better one.

Buy a more reliable and better quality system than a Flomasta!

 

[Harry Bloomfield]

It could be that a neighbour has the same thermostat and it is interferring with your receiver, they all come set on the same frequency so change your frequency settings settings it is very easy to do

It's not a frequency which is changed/selected, it is a code which is the DIL switch selects.

 

[PrivateMoment]

If it's less than a year old then it's still under guarantee, take it back and get a better one.

Buy a more reliable and better quality system than a Flomasta!

I...really can't afford one, mate. What an enormously helpful response on a DIY forum "Just buy a new one". Cheers.

 

[Madrab]

What an enormously helpful response on a DIY forum

We are not electronic engineers, these system are solid state electronics and are not serviceable.

If they fail or become unreliable then there is very little else, apart from what has already been suggested (batteries/reset/closer to receiver/etc), that can be done. If that all fails then they need to be returned/replaced.

Through experience, unfortunately I have found that the cheaper manufacturers always tend to have more issues like this, than the more mainstream makes, hence as a professional that's exactly the advice I would give any of my customers. Don't know how more helpful anyone else can be.

 

[jj4091]

Does changing the temp setting make any difference & is it one of these https://usermanual.wiki/Flomasta/Flomasta4718GManual1002605.486932721 if so have you tried ringing the helpline