# Thetford Poor Flush



## 100003 (Jul 11, 2006)

We have had our new motorhome for 2 months now and apart from a few minor hitches everything has been fine except for the Thetford electronic flush toilet. 
Whenever you press the button to flush the toilet all you get is a dribble that goes about 3-4 inches round the rim before trickling into the bowl. The dealer has replaced the actuator and water pump (which is the same pump as for both sinks & the shower). He fitted a restrictor to the output to get the water to travel further round the rim while we were away in France for the last 3 weeks, but of course this does not give any more water to clean the bowl, and we have to use beakers of water to clean the bowl. 
Admittedly the water pressure in the sinks seems a bit low but strangely the shower pressure seems quite good. 
I have sent a request for assistance to Thetford but I have not received any reply. 
One very strange thing that we have noticed is that if we turn on the water heater (Truma), after a while the water pressure, both hot and cold, is a lot better and the toilet flush is really good, but only for a short while. How this can be related is a puzzle to me. 
Does anyone have any suggestions or explanation for this problem? 

Keith


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## 89358 (May 20, 2005)

We get the same problem which is resolved by turning on each of the taps for a short burst, then the loo flushes perfectly round the bowl. I put it down to either an air lock or our system requiring a non-return valve on the tank side of the pump.


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## 100003 (Jul 11, 2006)

OverDrive said:


> We get the same problem which is resolved by turning on each of the taps for a short burst, then the loo flushes perfectly round the bowl. I put it down to either an air lock or our system requiring a non-return valve on the tank side of the pump.


Perhaps it is an airlock. I will try it tomorrow. Our pump is a submersible so fitting a non return valve could only be done after the pump.

Keith


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## DABurleigh (May 9, 2005)

"all you get is a dribble that goes about 3-4 inches round the rim before trickling into the bowl."

I'd get a PSA test PDQ.

Dave


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## mike800966 (May 1, 2005)

*Champ Dribbles*

Had a similar problem with our Champ.Don't tell anyone but I simply slid a brown rawlplug into the rinse spout, this had the effect of increasing the performance by reducing the flow a bit, anyway it now rinses fine! (I said Don't tell anyone 'cos I hoped I might get a tenner for the idea from a magazine!) Had excellent service from Thetford on another matter, I emailed the company and it was picked up by the rep who was most helpful. Must put a good word in the them as they were excellent, your lucky to have dealer who is helpful. 
The effect of the heater might be linked to the temperature rise causing the water to expand?. There seems to be a connection manifold under the wardrobe floor on our Champ. I wouldn't attack it unless I had to because all the connectors are plastic and screw together. The non return valve might help but it needs to be well upstream , close to the outlets and that might be easy to fit physically. Might it be worth checking the flow rate in the cassette compartment on that clear piece of hose? It might help to show if the toilet feed is blocked, on that subject I found a small piece of plastic swarf in the tank lodged in the pump pickup, only about 3mm across and that made a heck of a difference to the pump efficiency. 
Your not far away if you want to compare notes!!

Best wishes

Mike & Ann


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## chrisblack (Sep 10, 2007)

Having just drained my tanks to sterilise them, I'm getting no water at all through to my Thetford flush... all my taps are working... any suggestions on how to get the water back in there (I presume there is an airlock somewhere?

Thanks

Chris


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## seanoo (Mar 31, 2007)

hi there, i had the same problem in my autotrail and so did my friend. the problem on my van was a small orange restrictor in the feed pipe. when you open the cassette door look on the left and you should see a small clear pipe and in this pipe was the restrictor. i turned off the 12 v so the water pump cant operate and removed the pipe from the fitting. after this i took a pair of pliers and squeezed the little plastic thingy out. fully flushing toilet after no problems. if your not sure about doing this then dont and get your dealer to have a look for you. yours might be different but all the autotrails i looked at had the same restriction. hope this is of some use to you. all the best seanoo


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## pippin (Nov 15, 2007)

How come you lot didn't pick up on Daves clever retort?

"all you get is a dribble that goes about 3-4 inches round the rim before trickling into the bowl." 

I'd get a PSA test PDQ.


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## Waleem (Nov 1, 2006)

Chris
If your Dethleffs still has its original Thetford loo, it isnt connected to the water system in the van-it has its own internal pump and water reservoir, filled via the fold out spout inside the cassette door.


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## JohnsCrossMotorHomes (Jul 21, 2007)

pippin said:


> How come you lot didn't pick up on Daves clever retort?
> 
> "all you get is a dribble that goes about 3-4 inches round the rim before trickling into the bowl."
> 
> I'd get a PSA test PDQ.


MH dealers get blamed for everything!


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## bognormike (May 10, 2005)

pippin said:


> How come you lot didn't pick up on Daves clever retort?
> 
> "all you get is a dribble that goes about 3-4 inches round the rim before trickling into the bowl."
> 
> I'd get a PSA test PDQ.


yes, good spot, Pippin, a motorhome with prostate problems!


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## davesport (Nov 12, 2006)

Keith. It sounds like there may be an obstruction at some point in the pipework. The potable water tubing in my Hymer is approx 5/16 inside diameter & could easily be obstructed. The flush on my Thetford is powerfull enough to go all the way around the rim of the bowl. So much so that if I hold my finger on the flush button the water goes all the way round before dropping into the bowl just below where it came out of the nozzle :!: 

Things that I can think of to check.

1. Check that the pump is delivering "well" at its outlet. Is the pumps intake strainer clean ?

2. Check the water delivery at the pump side of the Thetfrod solenoid valve.

3. Examine the pipework. If the shower is flowing well it would suggest that the pump & its immidiate pipework are clear & working. Look at where the showers pipework tee's into the outlet from the pump & examine further downstream for problems.

4. Is it possible the pipes are furred up ?

Sorry I cant be of more help. It's going to be a process of logical elimination of the parts of the system found to be working until you find what's causing the pressure to be low at the outlets.

I would suggest that the higher pressures experienced after having the hot water on is down to expansion.

Dave.


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## chrisblack (Sep 10, 2007)

Waleem said:


> Chris
> If your Dethleffs still has its original Thetford loo, it isnt connected to the water system in the van-it has its own internal pump and water reservoir, filled via the fold out spout inside the cassette door.


Thanks Waleem

Trust me not to read the Thetford instructions properly... and what a coincidence that the loo ran out of water on the same day I drained my tanks!!

Chris


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## davesport (Nov 12, 2006)

Silly me for trying to think of sensible reply to a technical request :!: when all the time the tank was empty. 

I'm going for a lie down in a dark room :roll: 

D.


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