loirelover Posted November 13, 2021 Share Posted November 13, 2021 The hot water has been a bit hit and miss lately so I've decided that during the winter I'll try and cure the problem. The fan is the problem (not the fan for air circulation) and having removed the boiler I find it's the devil's own job to remove the fan! One bolt OK but a second is very difficult to get to! Any tips to ease this fan out? I've found an electronics company that can refurbish it but do you reckon they could do it in situ? TIA Link to comment Share on other sites More sharing options...
Derek Uzzell Posted November 14, 2021 Share Posted November 14, 2021 It’s most unlikely to be practicable to refurbish a combustion-air fan-unit while it is still in place on the Truma heater, but you could always ask the electronics company about this. You enquired about your 1998 Hymer motorhome’s Truma heater last month https://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/Truma-parts/58930/ and there was debate over which heater type (C3400/C6000 or C3402/C6002) your motorhome might have. I provided photos that you could use to tell the difference (which is very obvious) but the question of which Truma heater model your Hymer has remains unanswered. When it comes to removing the combustion-air fan-unit from the heater, I don’t how different C3400/C6000 models are from the later C3402/C6002 heaters, but whichever type of heater you heve, as it’s now out of your motorhome, removing the fan-unit should be straightforward (though not necessarily a piece of cake). You might have to DIY a tool to reach the hard-to-get-at bolt and - given the age of your Hymer - there’s bound to be a risk of the bolt being corroded in place. On the other hand, you’ve been able to undo the 1st bolt, so you might be lucky... Link to comment Share on other sites More sharing options...
loirelover Posted November 15, 2021 Author Share Posted November 15, 2021 Thank you for your reply. The Truma is C3400/C6000 and the access to the bolts is difficult for me anyway. I may take it to a motor engineers locally to see if they can remove it! Link to comment Share on other sites More sharing options...
Derek Uzzell Posted November 15, 2021 Share Posted November 15, 2021 The 1st attached image below is of an exploded-view drawing of a Trumatic C3400 heater and the 2nd is (I think) of the combustion-air fan unit. Unfortunately, neither image gives any clue as to how hard it might be to remove the fan unit from the heater. DIYers will (almost inevitably) come up against the sort of problem you’ve got, and I’ve had to grind down spanners to a thinness that allowed me to reach a particularly inaccessible bolt/nut or string together several tools to gain the required ‘reach’. But if you have a friendly motor engineer local to you, it’s likely they’ll have something in their tool chest that will undo the bolt. Link to comment Share on other sites More sharing options...
loirelover Posted November 23, 2021 Author Share Posted November 23, 2021 Thank you for all the useful info! In the end I took the entire unit to a guy in Cannock and he bench tested it. The issue has now been resolved thankfully at little expense apart from fuel to get to Cannock! I don't know if anyone has used this firm but he says units come from all over the country. If you have an obsolete Truma fan he can refurbish them with a 12 month warranty or even repair PCBs if that is the issue. Can't praise him enough, good set up, lots of equipment for testing! Link to comment Share on other sites More sharing options...
Derek Uzzell Posted November 24, 2021 Share Posted November 24, 2021 Which firm in Cannock did the work? I'm guessing it was A&R Electronic Developments Ltd https://www.arelectronics.co.uk/contents/en-uk/d17_Sales-and-Repairs-On-line-Shop.html but It would help if you could say if that's correct. Link to comment Share on other sites More sharing options...
keninpalamos Posted November 26, 2021 Share Posted November 26, 2021 Sounds like it wasn’t the combustion fan after all. If the fan doesn’t work then the burner won’t light. The fan purges any gas out of the combustion chamber before the igniter sparks. That’s why you can hear the motor run for about ten seconds before the ignitor sparks. If it didn’t and there was any residual gas left behind. You might be lucky to here it go bang. The c3400 and c6000 are almost identical to look at. The c 6000 was generally used in larger motorhomes. Both units boiler body were made of cast aluminium and had a vitreous coating and many became porous and leaked. (This is why it is best not to use the heating without water being present in the boiler even though the manual states you can. Truma later issued a service button saying this was incorrect and water must be present. The later stainless steel boilers were ok to run dry. The c3402 and c6002 boilers were stainless steel and have no interchangeable parts with the earlier two models. I have rebuilt one or two myself. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.