C2,C3,C4 are almost the same.
C2 Electric flush with pump in water tank
C3 Electric none return valve operated by the inboard water tank pump of motorhomes.
C4 hand operated pump these are the differences with the bench type design. Just to give you an idea.
Sounds very much like the flush tube is off the pump or side of toilet bowl. The following is going to be long but worth it so copy and paste into a word file.
First Thetford websote access followed by my pump repair/replace info which includes, obviously, where the pump is on the C2 toilet.
UK & EUROPE www.thetford-europe.com
Australia www.thetford.com.au (Even get request from Australian campers)
Australia site has stockist list.
HOME PAGE SELECT ENGLISH {if in Australia forget this selection)
NEXT PAGE SELECT CUSTOMER SERVICE (top line)
NEXT PAGE SELECT USER INFORMATION (left of pic) also 'Ask thetford' is on this page.
NEXT PAGE SELECT REPAIR INSTRUCTIONS (left of pic)
NEXT PAGE SELECT BUILT IN TOILETS [top right of pic]
NEXT PAGE SELECT This is where you select your toilet range. Search alll if unsure of type/range
NEXT PAGE PDF Files You should be in the pdf folder list on your Thetford toilet. Start downloading.
To direct link to the Thetford download site type in the following
www.thetford.eu/web/show/id=51498/langid=42
Don't bother for Thetford fridges they tell you for safety reason to take it to a service centre
PUMP REPAIR/REPLACE INFO
PAGE 1 OF 2
REPLACING / FREEING AN ELECTRIC PUMP IN C2 THETFORD CASSETTE TOILETS. Also added on page 2 is access to micro switches which has been added to my list by another camper with problems. He was kind enough to email me the information in case I had micro switch problems.
If you are not clear on what to do then e-mail me again.
FREEING A JAMMED PUMP
If you know there is current to the pump so go to ‘To access the pump’
An easy test to find out if current is reaching the pump carry out the following..
power up your 12 volt system.
Turn on the 12volt toilet cubicle light or if there isn’t one, one in the saloon area you can see [one over the sink/hob if there is one will do if like mine opposite toilet].
Press the toilet flush and take note if the light dims then goes back to normal on releasing the flush button. If it does it proves power is reaching the pump but the pump impeller is either jammed or the pump is knackered. Or use a multi meter.
If no current at all check the fuse in the holding tank housing, to the left I think.
Once in to tank check the flush tube is connected to both the pump and the side of the toilet. If yes carry on to remove pump then pull flush tube off pump.
To access the pump remove the toilet roll holder. PULL up on the holder housing this, it’s a push fit giving access to the water tank. It may need easing around the edges. Vaseline edges before replacing when repair completed to make further removal easy.
You will see the pump flush tube follow down in to tank and there is the pump in a cage held by one screw undo screw lift cage and pump from tank.
To free the impeller on jammed pump remove the pump as above turn it upside down and with small screwdriver turn the impeller about three turns until it feels to be running free . Don’t fix pump back in position just drop it in water, either in the tank or a bucket of water as long as It’s submerged [submersibles need to be wet, running dry damages them]. Oh! make sure the flush tube is still connected or you’ll get wet. If it works job done.
To replace a pump. WARNING! [ DON’T TRY PULLING EXISTING PUMP WIRE OUT FROM SWITCH CONNECTIONS YOU WILL NEVER GET THE NEW WIRE IN WITHOUT TAKING TOILET APART. SPLICE IN NEW PUMP WIRE.
Cut away the existing pump about six inches or 150mm up the cable from the pump and note one wire has a tracer [secondary colour] in the wire the secondary wire on new pump must be connected together don’t connect a plain single colour to a wire with a tracer colour. Fit on each of the wires one of the heat shrink joints then twist the wires together. One with tracer [Secondary colour] to the new pump wire with secondary colour. Then connect the two single colour wires together. Slide the shring joints over the joints and heat shrink them down. Then wrap tape around ends of shrink joints to ensure seal. Stow the joint section on the shelf at back of tank so it’s out of the water.
PAGE 2 OF 2
SHRINK JOINTS. [search internet for supplier if local shops don’t stock.]
You can purchase from car spares small shrink wrap sleeves heat sealed for the wire joints just remember to fit them on the cable before connecting wires together. Simply slide sleeves over joined wires and follow heat application instructions.
You could add some water proof tape after to be sure.
Re fit flush tube to new pump and test using a bucket of water to submerse the pump. Remember don’t test any pump dry it will damage them.
From another forum reader haven’t got his mail address.
volt drop can be a bitch to trace. could be a dirty / bad connection or switch. what ya need to do is test the cables with a low reading ohm meter. should get very low reading ie 0.5 ohms. (obviously with the switch in closed position) another way to test is to get some cable, run it from battery direct to pump (a similar length to what's installed) if the problem is still there the battery needs fully charging (even new ones can be down on power without a good solid charge up) if the pump works ok with temp wiring ya need to check voltage going into the first switch and then coming out, same with 2nd switch if 12v in and 12v out. this will tell if the switch contacts are dirty. *To see if the battery is fully charged or not, switch on a couple of lights and test voltage at battery terminals, should still give at 11v. with nothing switched on at all you should get at 13.2 volts. (6 cells at 2,2v /cell)
if everything checks out, ie battery good, 12v out of switches, then the negative from the pump to battery is suspect. again, can be checked with temp wire from battery to pump.
ACCESS TO MICRO SWITCHES.
1 The flush / blade button is removed by snapping off (its a push fit) the little button that has PUSH on it, and then you will need a LONG (8 ins approx) reach Phillips screwdriver (with quite a small tip, I bought 2 whilst we where away and they both where to fat at the tip.)
2 By removing the flush/blade button, It will allow you to remove the cradle that has both micro switches in it, (one you can see when the toilet is removed for emptying) this is the part when you will need a mirror and a lot of patience as the cradle is held in with 4 screws. And yes they are accessed with the collection compartment removed.
You gain nothing by removing the flush / blade button other than to remove the cradle that holds the micro switches. Unless you wish to give the exposed bits a good squirt of WD40, to see if that works, it would save lots of blood sweat and tears, as getting that cradle out and then back in is a pain.
Not ‘passing the buck’ but if I can’t help thetford may!.
Thetford have improved their site by adding downloads for minor repairs
www.thetfor-europe.com If I can’t help try them. You can also email them a question in ‘Ask thetford’. Or for Australia www.thetford.com.au yes give Aussies help too.
ADDENDUM: Pump repair/replace look also for a bad joint in cable if current drops or not showing and fuse is ok.
I did warn it was going to be long
Compiled by Lunar owner
Bob, April 2010
