Thetford toilet not flushing

Feb 27, 2011
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I see many posts on this subject. My own case was found this weekend on our first trip out in eighteen months. So it was my own fault really; I had dutifully drained down the system as usual before the winter lay-off but should have flushed it through as I have found that the pump is seized solid. While on site I googled and found some useful videos and after accessing the pump and trying to free it with long-nosed pliers, no joy - it will not move.

The genuine ones are very expensive so I will probably go for a cheapie one off ebay. Don't larf - it's worth a go but I'll still try to strip and clear the old one first. (My eldest son says I'm tighter than two coats of paint lol.)
 
Apr 20, 2009
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I had the same two weeks ago, seized solid, spray with WD 40 leave afew minutes and use a flat bladed small screwdriver to turn the propeller, moved after some initial force and then got easier and easier, workrd for me, give it ago.
 
Feb 27, 2011
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Tried freeing it off. It moved a bit, just a few degrees either way. I keep an old battery charger in the shed for 12v supply for instances such as this - connected it to the pump which spun about a 1/4 turn then stopped and blew the fuse in the charger plug. So it is well and truly beyond redemption. I've ordered an ebay one ("will fit Thetford models C200 etc etc blah blah") We'll give it a go and I'll report back after receiving it and fitting it in about a week once it arrives.

One idea I liked was to use car washer fluid, good for avoiding freezing of any fluid left in the pump even after blowing out the system and most have a nice fragrance. what does the team think?

Pete
 
Nov 11, 2009
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Tried freeing it off. It moved a bit, just a few degrees either way. I keep an old battery charger in the shed for 12v supply for instances such as this - connected it to the pump which spun about a 1/4 turn then stopped and blew the fuse in the charger plug. So it is well and truly beyond redemption. I've ordered an ebay one ("will fit Thetford models C200 etc etc blah blah") We'll give it a go and I'll report back after receiving it and fitting it in about a week once it arrives.

One idea I liked was to use car washer fluid, good for avoiding freezing of any fluid left in the pump even after blowing out the system and most have a nice fragrance. what does the team think?

Pete
I use car screen wash in the flush tank before during winter when it’s stored. I drain the tank of normal flush. Add about 1 litre of screen wash and pump some through.
 
Jun 20, 2005
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Reading this reminded me that I had this modification kit from Thetford FOC. I now have two drainage pipes. Maybe there are still caravans out there where the modification was missed?
Note the originator is our very own Nigel Donnelly!

 
Apr 20, 2009
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Tried freeing it off. It moved a bit, just a few degrees either way. I keep an old battery charger in the shed for 12v supply for instances such as this - connected it to the pump which spun about a 1/4 turn then stopped and blew the fuse in the charger plug. So it is well and truly beyond redemption. I've ordered an ebay one ("will fit Thetford models C200 etc etc blah blah") We'll give it a go and I'll report back after receiving it and fitting it in about a week once it arrives.

One idea I liked was to use car washer fluid, good for avoiding freezing of any fluid left in the pump even after blowing out the system and most have a nice fragrance. what does the team think?

Pete
Worth keeping on with it Pete, you have at least turned it both ways a few degrees, WD40 now and persevere, mine was the same kept working it. Dont connect it until it really feels free and loose.
I realise you have ordered a new one now but get the original working and at least have a spare.
 
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Feb 27, 2011
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Well. new pump arrived today. Fitted and working, very pleased with the pump quality, performance, and fit. Wiring was easy, the new one had three wires in its harness, and I just cut back the (yellow) earth wire and the brown and blue ones worked as per the original one.

Not sure how long it will last but hey ho, at 8.99 GBP posted a bit less cost than the genuine ones. No disrespect to Thetford but this one seems OK. Time will tell.

Next job will be to verify that the gas regulator has actually failed and if so the it will be replaced, not by a troublesome Truma, but by a Cavagna one. How the existing one has lasted the 16 years it has been on the caravan is amazing but having read the horror stories there is no way another Truma one will be fitted.

Pete
 
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Nov 11, 2009
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Well. new pump arrived today. Fitted and working, very pleased with the pump quality, performance, and fit. Wiring was easy, the new one had three wires in its harness, and I just cut back the (yellow) earth wire and the brown and blue ones worked as per the original one.

Not sure how long it will last but hey ho, at 8.99 GBP posted a bit less cost than the genuine ones. No disrespect to Thetford but this one seems OK. Time will tell.

Next job will be to verify that the gas regulator has actually failed and if so the it will be replaced, not by a troublesome Truma, but by a Cavagna one. How the existing one has lasted the 16 years it has been on the caravan is amazing but having read the horror stories there is no way another Truma one will be fitted.

Pete
A good result on the toilet pump.

Re Regulator. A lot of OEM ones seem to be Truma and to be honest regulator issues don’t crop up very often on the Forum. If it’s lasted 16 years you’ve got around 6 years beyond what I would call the change out date. Mine will be replaced at the next service due December this year.
 
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Feb 27, 2011
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Many thanks Otherclive. Just got the regulator off (the screws into the bulkhead were very tight and a pain to remove lol)

The while the regulator is 16 years old, the pigtail is much younger, supplied by our dealer when we bought the caravan. A few days ago I established, by briefly turning the bottle on and off with the pigtail disconnected from the regulator, that the pigtail is not blocked. Now that the regulator is detached from the bulkhead, with the regulator held outside of the gas locker, a brief turn on/off shows that the reg is completely blocked. So I'll go ahead and order a new one. (there is no sign of reset button/s on either the regulator or pigtail!)
 
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Feb 27, 2011
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New regulator ordered, decided to go for a Cavagna, very good reviews. Also ordered some collared olives - I have some 8mm pipe and I'm going to mount the new regulator higher than the existing one, which is the same height as my second bottle (Calorlite). As the caravan is 2005, in my opinion the regulator deffo needs to be sited higher (there is plenty of room for this)

Reports later once I have all the bits and have (hopefully successfully) fitted it and got the gas all working well.
 
Nov 16, 2015
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Do you carry a spare like a spare power supply then? Odds are one would go at the most awkward time.
OC, yes I do. ☺, after a failure of a power unit when away in Ludlow for a week, I had a round trip of 170 miles to get a new unit. And as I was also doing a lot of touring in France I decided that it was prudent to get the failed one repaired.
 
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