Worc greenstar 24i junior intermittent timer fault

[TFGplumbing]

Heya guys

Got a bit of a head scratcher here, I serviced this 24i Junior GS a couple of weeks back. It was fine no probs. A chapel owns the boiler and they have been having some issues with the timing. They have a dt20 + wireless stat, I believe its one of the older ones as the room stat does not have the round dial to adjust the temperature; it has plus and minus buttons either side of the digital dispaly. Anyway I set the programmer up just how they requested only to come on 8:30 - 11:30 sunday morning for their service. People are in and out during the week, in such cases they set the heating to ''on'' and put it back to timed when they are finished.

The problem - the Dt20 programmer unit keeps on setting itself(on the heating side)to ''off'' randomly no matter whether the boiler set to ''timed'' or ''on'' its very strange not come across anything like this before. I replaced the Batteries in the wireless room stat as the unit had lost signal. I also noticed that the select button was not working (heating side) and would not move the digital selector arrow. After a bit of fiddling it started working again. Got a call back earlier... same problem the Dt20 programmer unit keeps on setting itself(on the heating side)to ''off''

I think the DT20 unit is shagged. any ideas?

 

[R1CKY]

Fit an external programmable stat, the older DT20 always seem to play up.

 

[mfgs]

Those wireless stats are awful, replace it with a nice Honeywell one.

 

[TFGplumbing]

Had alot of these 24i's playing up recently! I was thinking just D/C the dt20 temporarily and have them run it manually off the boiler stat, just to see if they have any further problems. Just to rule out any faults with the boiler, I have had some real niggley faults with the 24i's, even had a duff loom on one!

 

[mfgs]

It wont be the boiler, it will be the receiver at fault.

 

[TFGplumbing]

It wont be the boiler, it will be the receiver at fault.

I'am inclined to agree.

Thank you for your help guys

 

[vern]

I'am inclined to agree.

Thank you for you help guys

DT 20 crackered wonder it's lasted this long on a mark 1, deffo this as heating selector goes to off as software default, so heating can't stick on in case of comms loss etc....

new DT20 rf mark 2 or honeywell cm927 but you will loose preheat control!

 

[TFGplumbing]

It must be around 6 years old this install..Are the new DT20's compatible with the older 24i's? I assume the probably are

 

[vern]

It must be around 6 years old this install..Are the new DT20's compatible with the older 24i's? I assume the probably are

Yes pal, change both ( transmitter and receiver) as a pair as frequency has changed and mk2 has a stronger signal, this will sort it, nothing to you and service either! Although powering down tends to start this trend off just for info!

 

[TFGplumbing]

Yes pal, change both ( transmitter and receiver) as a pair as frequency has changed and mk2 has a stronger signal, this will sort it, nothing to you and service either! Although powering down tends to start this trend off just for info!

Ok replaced the old dt20RF today with a nice shiney new dt20RF as requested by custard.. ****ing hope this solves the problem of the signal dropping, if not i'am going to go mental haha 🙂