Another thermostat thread for home boiler

[dieselboy]

This thermostat is actually doing my head in. changing the chanel makes no difference to it's operation, it still plays up.

What its doing is when it receives the signal to turn the boiler on the relay in side makes noise and the green light illuminates to say its on but the boiler doesn't do anything. The easy to fix it is to turn the stat down so it sends the off signal, reboot the receiver unit then turn the stat up so it tries to come on again and then it works.
The same happens when you want it to go off, the receiver has difficulty turning the boiler off and instead the boiler will just keep providing water to the radiators.

I'm about to pull this thing off the wall and see if anything inside can be cleaned etc..

Any suggestions? Apart from replace it. Thanks!

[gwh200]

Just replacement tony. There's many things to go wrong with a non analogue t/stat. They're not generally repairable.

[dieselboy]

Thanks graham I won't bother touching it then. I just bled the rads and had to fill the system up twice because the pressure dropped off the scale and the boiler shut off.

Si tate if you see this mate can you recommend an engineer to replace this stat with something that's not so temperamental? I'm not so keen on the ppl that have been out here to do the work in the past. Cheers!

[Koi]

Drayton digistat RF1 are pretty good.

Also if the pressure in the system has dropped it would suggest theres a leak somewhere ??

[Jools T]

Just out of interest, what stat is it, and to what combi is it connected?

Keep an eye on your pressure, if it keeps dropping and you need to keep bleeding rads, especially on the top floor you deffo have a leak on the system.

My mate is a Gas Safe registered engineer, based in Horsham but covers most of South London. Let me know if you want his no.

[dieselboy]

Thanks for your replies.
The boiler is a Feroli and the stat is a Salus RF500.

Nigel do you think it's worth going for another wireless stat? Apparently it has been working fine up until the past few months. And it was working all day after I gave the receiver a "reboot" by unplugging the UK mains from the receiver and plugging it back in again.
Here are the symptoms: the receiver clicks "on" but doesnt actually tell the boiler to come on, or clicks off but doesnt tell the boiler to go off, and sometimes the stat "says" the heating should be on but the receiver's green light isn't illuminated. The only way to fix this for however long is to power off the receiver and power it back on again.

Regarding bleeding the system, the upstairs rads were only half warm. I bled two and on bleeding the air just stopped coming out and there was no water coming out either. I went downstairs and the boiler registered a Fault for lack of system pressure and the guage was not even on the zero. I filled up to 1.2 bar and began bleeding again and same thing happened although water did come out by the time the pressure had dropped - this was on the 3rd rad. I filled to 1.5 bar this time as couldnt find the rated spec in the manual and our one at home is normal range 0.8 to 1.8. I bled the others and they were all okay.

The engineers had set the radiator boiler outlet temperature at 39c so was taking ages to heat the bungalow up.
The boiler has a setting to keep the heat exchanger at around the set tap water outlet temp so I turned that off so as to stop the boiler constantly firing up every so many seconds.

At least the place was warm when I left. Hope it doesn't play up until I can get someone to sort it. Her place is in Scarcroft, Leeds. Probably too far but thanks for the offer

[ziggy]

Thanks for your replies.
The boiler is a Feroli and the stat is a Salus RF500.

Nigel do you think it's worth going for another wireless stat? Apparently it has been working fine up until the past few months. And it was working all day after I gave the receiver a "reboot" by unplugging the UK mains from the receiver and plugging it back in again.
Here are the symptoms: the receiver clicks "on" but doesnt actually tell the boiler to come on, or clicks off but doesnt tell the boiler to go off, and sometimes the stat "says" the heating should be on but the receiver's green light isn't illuminated. The only way to fix this for however long is to power off the receiver and power it back on again.

Regarding bleeding the system, the upstairs rads were only half warm. I bled two and on bleeding the air just stopped coming out and there was no water coming out either. I went downstairs and the boiler registered a Fault for lack of system pressure and the guage was not even on the zero. I filled up to 1.2 bar and began bleeding again and same thing happened although water did come out by the time the pressure had dropped - this was on the 3rd rad. I filled to 1.5 bar this time as couldnt find the rated spec in the manual and our one at home is normal range 0.8 to 1.8. I bled the others and they were all okay.

The engineers had set the radiator boiler outlet temperature at 39c so was taking ages to heat the bungalow up.
The boiler has a setting to keep the heat exchanger at around the set tap water outlet temp so I turned that off so as to stop the boiler constantly firing up every so many seconds.

At least the place was warm when I left. Hope it doesn't play up until I can get someone to sort it. Her place is in Scarcroft, Leeds. Probably too far but thanks for the offer

Hi it might be the pump on the way out,or the system needs flushing they get clogged up over time, but if your losing pressure does sound like a leek in the system to me

[Pelicanbill]

I do heating. I assume you have put in fresh batteries into the wireless transmitter and also I would make sure the wired connections between the receiver and boiler are tight cause it sure sounds like a possible loose connection butting in! Also make sure that no loose wires are touching the others as this could also cause extraneous issues.

You could also remove the wires to the receiver and just loop the terminals to make sure the boiler runs ok on it's own boiler stat. Another thing, if the stat starts creating problems at a higher setting rather than no problems at a low setting this also points to a bad connection on a pc board.

At it's simplest, if the boiler is working correctly then it's a fault with a stat. I've got a spare honeywell T6360 room stat that you could hard wire into the boiler for testing purposes. You can have it on free loan if you want ... it surplus to requirements.... just pm me your address and I'll send it to you for a pint

oh and another thing depending on what was done, and I doubt anything substantial - if no leak then I expect your system needs a decent flushing out + protector added.

[blackpoolsparks]

Did you change the address on both the thermostat and the receiver?

[dieselboy]

Did you change the address on both the thermostat and the receiver?

Have some faith in me - I'm not that stupid!

ps I setup wireless networks for a living

PelicanBill, how does the thermostat control the boiler? There is a COM and another wire which I cannot remember. Are these two simply connected or open to turn the heating on or off?
Now you say about a loose wire, it could be that.. When you turn the stat receiver unit on and off the red light that shows power gradually illuminates. But that is on a 230v system so would have thought I would hear arcing?

Ziggy, the boiler was fitted in 3rd quarter of 2008. I'd hope it isnt the pump. At the moment I just want the heating to come on and off when it should and like it should. Right now it's getting stuck on or stuck off and fiddling is needed to get it going again. If the pump was on its way out then would the boiler start and run or attempt to run if the stat circuit was working properly? Because at the moment the display on the boiler doesnt even say its going to fire and the fan doesnt spool when its stuck off and when its stuck on the display shows its providing heat to the rads.

[dieselboy]

Again thanks all for your replies and helping me!

[Pelicanbill]

Have some faith in me - I'm not that stupid!

ps I setup wireless networks for a living

PelicanBill, how does the thermostat control the boiler? There is a COM and another wire which I cannot remember. Are these two simply connected or open to turn the heating on or off?
Now you say about a loose wire, it could be that.. When you turn the stat receiver unit on and off the red light that shows power gradually illuminates. But that is on a 230v system so would have thought I would hear arcing?

Ziggy, the boiler was fitted in 3rd quarter of 2008. I'd hope it isnt the pump. At the moment I just want the heating to come on and off when it should and like it should. Right now it's getting stuck on or stuck off and fiddling is needed to get it going again. If the pump was on its way out then would the boiler start and run or attempt to run if the stat circuit was working properly? Because at the moment the display on the boiler doesnt even say its going to fire and the fan doesnt spool when its stuck off and when its stuck on the display shows its providing heat to the rads.

OK .. I'll be as succinct as possible! The fact that the boiler fires is a good sign. I am assuming it is a combi (hot hater on demand) rather than a system (heating cylinder) boiler. The wiring set up for a typical feroli boiler is a VOLT FREE connection between boiler and stat. So your receiver will have no link and will be wired up as per volt free ... ie: live feed and neutral from mains (maybe via boiler) to the L and N on the receiver and 2 (volt free) wires going from the com and NO terminals on the receiver connected to the 2 terminals (possibly numbered 72) on the boiler. I would check that no strands of wire are touching either terminal. also, it doesn't matter on volts free terminals which wire goes to which terminal. J
As the boiler was working ok before, I would assume that the stat is at fault rather than the boiler simply because it easier to wire out the stat - just replace the 2 wires on the boiler with a link - it volt free so no harm Of course, if you don't understand what I'm saying just do not proceed.

I'm working (well, I will be once I've sent this) but I can talk you through it if nec. pm me your number - I should get it on my phone ish/maybe/if it not sulking

[slobodan]

pm me your number - I should get it on my phone ish/maybe/if it not sulking

He can't, he's a sarf londoner, his sub money was spent on a kebab.

[dieselboy]

OK .. I'll be as succinct as possible! The fact that the boiler fires is a good sign. I am assuming it is a combi (hot hater on demand) rather than a system (heating cylinder) boiler. The wiring set up for a typical feroli boiler is a VOLT FREE connection between boiler and stat. So your receiver will have no link and will be wired up as per volt free ... ie: live feed and neutral from mains (maybe via boiler) to the L and N on the receiver and 2 (volt free) wires going from the com and NO terminals on the receiver connected to the 2 terminals (possibly numbered 72) on the boiler. I would check that no strands of wire are touching either terminal. also, it doesn't matter on volts free terminals which wire goes to which terminal. J
As the boiler was working ok before, I would assume that the stat is at fault rather than the boiler simply because it easier to wire out the stat - just replace the 2 wires on the boiler with a link - it volt free so no harm Of course, if you don't understand what I'm saying just do not proceed.

I'm working (well, I will be once I've sent this) but I can talk you through it if nec. pm me your number - I should get it on my phone ish/maybe/if it not sulking

Thanks for this. My nan lives in Leeds and I live / work in South London. I just drove up this weekend to take a look and it's working at the moment but I want to get that stat replaced or at least find why it isnt working and fix permenantly. As I live down here its a few hours drive each way so only had the Sat / Sun to look into it.
I read about the volt free setup in the manual and could see how it was wired by looking at the stat receiver. I didn't look at the terminals on the boiler as it involved removing the cover and I didnt see the need to at that time. There doesnt appear to be any loose strands of wire in the terminals on the receiver though.
The link you mention is just effectively connecting the the two wires together from the boiler to short them. Doing this would tell me if the receiver for the stat was doing its job propperly or not. I suppose I could have measured the resistance between the COM and the other side of that connection when the relay clicks.

I do need to sort my subs out.

[Pelicanbill]

He can't, he's a sarf londoner, his sub money was spent on a kebab.

I didn't look ...... and I'm a Sarf Londinner who moved to Sarry before ending up in not quite so posh Cheshire!