Truma Blown Air Heating

Sounds like the transistor that lurks under the heatsink. If it is I have some spare and happy to send you one. Do be careful with those pins!
 
2021-11-09 16.39.49.jpg
The fan control transistor is under this heatsink
 
Hi H,
Interesting our pub should be back by now with clean bill of health so will check connection to fan?
Caravan doctor is also checking several other items so hopefully we will get it working!
Which area of the country and you might want an introduction to your specialist.
Mike
 
Hi H,
Interesting our pub should be back by now with clean bill of health so will check connection to fan?
Caravan doctor is also checking several other items so hopefully we will get it working!
Which area of the country and you might want an introduction to your specialist.
Mike
I live on Walney Island, Barrow in Furness Mike. I'm going to have another go at it tomorrow, just clearing out the flue and giving the burner a blast with compressed air. I will probably take Martin up on his offer of a replacement output transistor for the PCB and see how we go from there. Tomorrow promises to be not too bad a day weather wise and now I have access to the thing I might just get lucky😉.

Here's an interesting article. https://motor-roam.co.uk/truma-trumatic-c3402-boiler-inspection-troubleshooting

Cheers

H
 
On mine if I want hot water and heating the heating won't start until the waters hot
 
On ours the red light has come on occasionally but by just switching off and back on again has done the trick. Maybe a sign of some pending issue but will cross that bridge if and when it happens.
 
View attachment 103449 The fan control transistor is under this heatsink
Thank you for the transistors Martin. My tame electronics engineer changed it for me, no chance of my eyes being up to it, and nothing has changed unfortunately. My focus has now changed to a "thermostat" situated between two warm air outlets at the bottom of the honeycomb heat exchanger that the circulation fan feeds. It looks to me to be a thermistor so a tickle with a heat gun could tell me something about the way its resistance changes with heat. I am however partly minded to bite the bullet and go for a Combi 6E because I"m minded to extend my grandad's entitlement on my licence next may and get three more years out of the van.

I'll keep you in the picture and thank you for your help and interest.

Cheers

H
 
Sorry to hear the transplant not a success. Was hoping to hear good news.
Yup same here although progress has been made, in as much as I have the beast running but it seems not to like the remote "room sensor" which is just a thermistor. I have, of course, managed to destroy the existing one trying to get it out of the panel but a replacement is on order and if that fails £29 spent which makes a grand total of £60ish which I'll take on the chin. The main thing is we now have heating and we can switch it on and off as we please. It is on a final warning though, any more grief and its goodbye C3402 and hello Combi 4E (and about £1400) but there's no pockets in shrouds.

Cheers

H
 
Sorry to hear the transplant not a success. Was hoping to hear good news.
Latest news Martin. After going through all the palaver with changing the Mosfet (thank you for supplying the bit) I put it all together and the thing fired up and ran the circulation fan as well but only at a single, fairly high, speed. I then realised I hadn't connected the room temperature sensor. Connected that up again and the erratic speed returned. £28 quid for a replacement sensor and it is a happy unit again. Not cast iron conclusive having had all the connectors off and on a few times but that's where we are. I do find it a bit odd that the sensor, essentially just a thermocouple, went faulty in the way it did but I suppose it is still a semiconductor after all and probably can be ''zapped'' by a voltage spike.

Thanks again for your help.

Cheers

H
 
I have this very problem:-( I bought and installed a diesel heater, nice and toasty and so far no problem....
 

Users who viewed this discussion (Total:0)

Back
Top