Heating coming on with hot water Worcester 24i rsf

[Alexx89]

Evening,

Been a long time lurker of this fine forum.. Been trouble shooting a problem with my parents caravan boiler for them, a Worcester 24i rsf.

Had the PCB replaced last year but soon after the heating would come on with the hot water, gas bottles aren't cheap either on this site

Anyway.. I sourced and put a air switch on it after reading a thread on here but it hasn't sorted it.

After some more searching I've found flow switches for the same boiler that look like brass fitting that sits between pipes. After locating what I think is the same part on this boiler it seems to be on the cold water inlet?

Any ideas what to do next? The site is pretty remote so getting anyone out to look at it is not cheap, I've worked on camper van and caravan boilers in the past so feel confident tackling this but wouldn't attempt anything I wasn't sure of.

Many thanks!

 

[hertsboilers]

Another PCB!

 

[picasso]

I would think the wrong circuit board has been fitted or fitted badly

 

[Alexx89]

Really? The guys response was the usual wouldn't be anything that I've done.. To be honest I'm 50/50 weather the issue was present before he did the PCB

 

[picasso]

Your boiler has a biflow heat exchanger so the pump only runs on ch demand or to cool the heat exchanger after running off hot water, how many rads do you have connected to the boiler ?

 

[Alexx89]

Your boiler has a biflow heat exchanger so the pump only runs on ch demand or to cool the heat exchanger after running off hot water, how many rads do you have connected to the boiler ?

I see, 7 radiators all pretty small though as it's a static caravan. The guy who did it was actually on site last week but still wanted a callout fee and stated it wouldn't be any thing he had done wrong.. The usual.

Cheers

 

[hertsboilers]

Simple. measure if you have 230v power to the pump when hot water is on.

 

[Alexx89]

Simple. measure if you have 230v power to the pump when hot water is on.

Will do, I think I have my MM in the car (I'm a mechanic) so there shouldn't be 230v at the pump when the hot water is on yeah?

 

[picasso]

Correct, which thread were you reading that convinced you to change the APS ?

 

[hertsboilers]

Simple. measure if you have 230v power to the pump when hot water is on.

Will do, I think I have my MM in the car (I'm a mechanic) so there shouldn't be 230v at the pump when the hot water is on yeah?

Yes

 

[Alexx89]

Cheers.. Turns out I don't have my MM with me, damn.

The PCB was fitted nearly a year ago.. I reckon the bloke who did it will likely stick to his story about it not being his fault and disregard any of my findings anyway

 

[Alexx89]

If wiring diagrams are available and the PCB is the right one just not fitted correctly I should be able to sort it myself.

 

[ianmcd]

well if you dont have a multi meter with you run the hot water and see if the pump runs , Take off the large screw in the middle of the pump ( a small amount of water will come out thats normal) and see if the shaft of the pump is turning or you may be able to feel the pump just by touching it to see if it is running

 

[Alexx89]

Thanks, took off the screw with the hot water running and the shaft was turning, left the cover off and ran the hot water again and it didn't start turning again.

Appreciate the advice

 

[ianmcd]

The shaft should only turn with CH demand, when a hot tap is opened then shaft should stop turning then when the HW tap is closed the shaft will turn again if CH is being called for