GlowWorm CXI 30 CH not staying on

[aadster]

my boiler is working fine for DHW but CH is not staying on for more than a few seconds. I see the temperature rise to 72C, well above the 40C requested, then it stops.
Firstly, its not shown me any error codes, and the Bar is correct and not flashing, but when I hold down Mode I can see what appears to be a log, with 4 entries of F22 (temp rise too quickly / low pressure) .. now whether this is from a while back, i.e. before I bled the radiators or not I dont know, but F22 does tally with the temp rise and scarily suggests a blockage / dead diverter valave!
Id like to reset the log, so I can be sure its not an old message, but even when I hold down reset, the F22s are still there.

I am insanely broke at the moment so really dont want to go on a goose chase replacing parts on a 2 / 3 year old boiler and finding its not solving the problem, so any suggestions, such as being able to fire the boiler without using the wireless control (to be sure its not just a problem with that!) before I call someone out would be a life-saver right now!
Thaanks!!

 

[mickyg]

Just for everyone elses reference, I should firstly point out that your boiler is an Ultracom CXi not just a Cxi, 2 totally different boilers !

firstly can your provide us details of what you use to control the heating. You mentioned a wireless control?

There is a way to get into the S codes to see what the boiler is actually doing, or "thinks" it is doing, but if you don't have the manual to hand its better we start from the basics.

 

[aadster]

ahh yes thanks, its an Ultracom 30cxi, the wireless control unit on the boiler is a Salus RT300RF and the handheld unit is a RT300TX.
Thanks very much!

ps I should also add that when I switch the boiler off at the wall, wait 1 min, switch back on again, increase the temp on the controller, it triggers the green demand light on the RX unit and I hear its relay click, but I see absolutely no change with the boiler,... I cant remember precisely what Ive been doing to get it to fire briefly

 

[aadster]

well I found the d and s menus looked - d8 is always 0 and the state is always 30 whether the green light on the RX is on or off (changes correctly when i provide DHW demand) ... so looks like its either the relay in the RX unit or the PCB has a defect.. either way, it doesnt seem to think I even want any CH!

To test the relay, can I just bridge the COM / NO connections at the back with some sort of rubber handled insulated metal thing? I would have assumed that if NO was disconnected that would mean "yes", but when I tried removing the connection i still have no d8 demand

UPDATE: Salus have a dedicated phone line which I'll try tomorrow: 08700 766902 .. although I suspect they wont hand out electrical advice!

 

[GuessMan]

A good example of why novices should not play with electrics, especially with rubber handled thingies. NO means normally open, ie not switched in its deactivated state.

If it is a Salus assume it has failed! Bridge the connection with a wire link ( only once you have isolated the power) and then check the status on the boiler.

 

[aadster]

er, well no its an example of why its a bad idea to try humour at 12:08am on a Friday night!

This is however, a very good example of how following advice on this forum can save you hundreds of pounds and warm your feet!.. bridging the connection worked! I now have CH and my bank manager can breathe a sigh of relief at only having to fork out for an RX unit!

Thanks a million everyone!!