Worcester 24i Junior will not fire up in heating mode

[nobbyumbnut]

Hello,
Desperate for an expert opinion. I have a worcester Bosch 24i junior that has just stopped firing up on heating demand.
Hot water all OK.
I have a Drayton digistat rf/sr set up. I have tried the usual re-sync etc.

When I depress the over-ride button nothing happens. the over-ride LED comes on but nothing else.

I think that the fault is with getting a run signal from the digistat receiver. What voltage should I read on connection CL in the boiler (this would be connection 3 in the dgistat receiver)

Can I temporarily bridge between L and CL on the boiler to prove the reciever faultly as I suspect.? I would never consider runnin the boiler with bridge in of course. just want to eliminate the receiver.

Any help would, natuarally be, gratefully appreciated.

Thanks

Nobbynumbnut

 

[dreadnoughtheating]

Try replacing the battery(ies) in the RF stat first.

DH

 

[nobbyumbnut]

Thanks for the quick response. i have re-newed the batteries and re-synced. Still no Joy.

 

[londonboy]

is the light green on the receiver

 

[nobbyumbnut]

Hello,
Yes the green light is on on the reciever.

I am getting 240v at the connection CL on the boiler. I think that is telling me that I am getting the rn signal from the receiver but nothing else happening. I have had the PCB out and there is some schorching around four resisters and relay R1 shows signs of carbon/ burning on the contacts.

New PCB I think.

Ayone know where a good place to buy a PCB.

Cheers

 

[bengasman]

Sorry to say, but both the stat and the boiler are problem cases. The good news is that it is perfectly ok to remove the roomstat connections in the boiler, and bridge them.
Provided you can safely work on 230V that is.

 

[nobbyumbnut]

Bengasman
Which connections do I bridge out?

 

[Agile]

If the transmitter unit is some way from the receiver it sometimes helps to move the TX unit close to the RX unit.

When you perform the re-sync its ESSENTIAL to follow the instructions EXACTLY as written. Few people seem to be able to follow the simple instructions!

The good news as Ben says is that you can bridge the output connections for as long as you like with no problems. Thats if safe to work on 230v !

Tony

 

[bengasman]

Bengasman
Which connections do I bridge out?

Provided that the stat is wired up correctly, you remove the 2 signal wires from the boiler, and put the bridge where they were.
Unfortunately, it is quite likely that yours is a cowboy install, and can not taken for granted that all is as it should be.
Verify the wiring in the M.I. would be my advice.

 

[nobbyumbnut]

Hello,
Yes the green light is on on the reciever.

I am getting 240v at the connection CL on the boiler. I think that is telling me that I am getting the rn signal from the receiver but nothing else happening. I have had the PCB out and there is some schorching around four resisters and relay R1 shows signs of carbon/ burning on the contacts.

New PCB I think.

Ayone know where a good place to buy a PCB.

Cheers

 

[nobbyumbnut]

Well I'll be Bu**ered.
I linked out the room stat as you suggested and the blessed thing fired up.

I bow to your superior knowledge.

Thank you, Thank you, thank you!!

What now?

 

[nobbyumbnut]

Well I'll be Bu**ered.
I linked out the room stat as you suggested and the blessed thing fired up.

I bow to your superior knowledge.

Thank you, Thank you, thank you!!

What now? I guess a trip to theroomstat shop!

 

[bengasman]

I should know, I only install Worcesters, and usually with a rf stat.
I used to use the drayton rf1, which is what I expect you have, and they are notorious for loosing the connection; they are a right pain in the proverbial, and I ditched them. To add insult to injury, their "tech help" tried to fob me off a couple of times; they pretended not to be aware of any problems and insinuated I hadn't hooked them up right.
If you can't reset it, for which you will need the manual, I'd recommend the siemens rev24rf, the best I have found so far. Honeywell cm927 is only slightly less, but still pretty good.

 

[nobbyumbnut]

A siemens unit it is then.

Once again thankyou.

Bob (warming up nicely)

 

[picasso]

I think your trying to connect to the wrong connections, L and CL are for a programmer , you should be connecting your reciever to RN RI and rl , put the link back in across C1 and CL.