Jump to content

Truma 3002 Fan Stops Working When Hot.


Recommended Posts

Hi All, I'm hoping you can help diagnose my heater problem. It is a Truma 3002. A short while ago it stopped working. I finally got round to trying to fix it. The 12v goes to the fan pcb then on to the fan speed switch ok. That's where I lost it, it didn't seem to be coming back from the switch. I removed the fan unit, cleaned it, removed the fan pcb, couldn't see anything obvious, and also removed the switch. I put 12v straight on the fan and it turned well. Hooked it all up with covers etc off and it worked in manual and auto, broke it down put it back together properly and at first, while it was cold it was working fine. After about 10 mins when it was hot the fan slowed down gradually then stopped. The fan sounded a bit rough as it was slowing down.

 

Sorry for the long post, has anyone any suggestions as to which part of the system might be on the blink, fan itself, fan pcb or switch?

 

Thanks,

shamrockbob.

Link to comment
Share on other sites

If on auto the fan should slow down when the caravan heats up and also reduce to 1kw from 2 kw and then the element will cut in/out as required, i don't think the fan should actually stop but certainly vary in speed when operational.

Link to comment
Share on other sites

I have similar problems with the same unit on my van. Set on auto the fan will stop when it gets hot, and will stay off until I push the connector to the switch on the metal frame back on. It will always work on manual. If It could be explained I would be very interested.

Bill

 

Growing old is compulsory, growing up is not.

Link to comment
Share on other sites

I would look to see if your heater installations are fitted with the Truma remote temperature sensor. It is a black dome shaped fitting about 15mm in diameter and could possibly be positioned near the ceiling in a caravan. It works in conjunction with Ultraheat electric heating and afaik acts as a thermostat. If the remote sensor is positioned in a place of high heat or heat accumulation it could affect the running of the fan.

 

My thoughts are only a possibility, but is the fan also affected if only running the Truma heater on gas?

 

John.

Link to comment
Share on other sites

Nothing to do with the ultraheats remote sensor as the fan has it's own inbuilt sensor and so entirely independent of the heating. ...mores the pity or the heating would work better?!

The fan should then speed up as heat increases and eventually slow down once temperature of air being pulled through the fan housing cool sufficiently.

 

So my first guess is the motor, have you checked the lengthy of the brushes and how far down their slots they are?, originally the top of the brushes is level with the top of their holders. badly worn ones will have little pressure left from their hair springs, also being noisy indicates the bearings are also worn due to a lot of use?

 

Reasoning is, heat causing a connection to expand and weaken so preventing enough voltage to pass and drive the fan, it could then equally also be a loose connection between switch and pcb or the switch itself is faulty

gary1s.gif

 

Arc Systems are specialist Carver caravan product repairers, committed to providing a comprehensive service as well as spare parts for these popular heaters.

Link to comment
Share on other sites

Thanks All for the responses.

 

Gary, I'll pull the fan off again and check the brushes. Never thought of those last night.

 

The fan runs most of the time. I live in the caravan Mon to Fri for work. Is there a bearing replacement kit available? What about replacement brushes?

 

Cheers,

Shamrockbob.

Link to comment
Share on other sites

Well I pulled the motor and the brushes are very worn. I cut some hard plastic I have into tiny squares and put it on top of the brushes to give a bit more tension. The little springs a ***** to get back in place when they unwind. I also went around all the connectors on the fan pcb and the cable and squeezed the metal tabs closer together. The fan is back in and working normally at present.

 

It doesn't look like the brushes are easily replaced. Am I correct in assuming that when they go the motor needs replaced?

 

Cheers,

Shamrockbob.

Link to comment
Share on other sites

Well done on packing out the brushes, this should give you quite a bit more life until a brush finally lacks support enough to twist and jam!

Tip for pulling back the the hair spring is to ask nicely if the other half will loan you a small crochet hook! :unsure:

 

Truma did once do replacement brushes but that's long ago so sadly it's now a new expensive motor :(

gary1s.gif

 

Arc Systems are specialist Carver caravan product repairers, committed to providing a comprehensive service as well as spare parts for these popular heaters.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...