Jump to content
Gordon of Essex

Dometic CTW 4050 Flush leaking into bowl

Recommended Posts

I can't find anyone who seems to have this problem, when I refill the flush water a lot of it leaks into the toilet bowl. This doesn't seem to happen immediately as I can be watching through the window while I'm filling from the outside. I have previously filled it, checked it's alright and returned an hour later to find the bowl half full of pink flush water. Not only is it wasting the pink solution but also filling the toilet cassette far too quickly. I am quite mechanically minded but I can't work out what's happening. Has anyone else had this problem and managed to correct it?

Share this post


Link to post
Share on other sites

I'm not sure of the construction of the 4050 but I assume it has similar features to a thetford toilet.

 

My initial guess would be a lack of vent to the flush tank, air at the top of the tank heating up, expanding pushing the flush water down the tube. Try leaving the filler flap open and see if it still does it, if not, look for a blocked vent.

 

The only other part that's involved will be an anti syphon valve but it wouldn't really fit the symptoms you have.

 

AJG

Share this post


Link to post
Share on other sites

Thanks for the reply. Sorry about the delay in replying back, I've been away. 

 

There's a flap on the outside then a quarter turn cap, it looks like it vents through the cap. I've disassembled the cap and everything appears to be as it should be, no dirt, broken spring or anything like that. Plus after reassembling I can blow and suck through the vent hole in the cap (after making sure it's clean) so I don't think it's that. 

 

I had hoped someone would say, "that happened to me and all I had to do was-----"

 

I'll try leaving the cap off next time I'm away, although I'm doubtful about whether it'll help

 

 

Share this post


Link to post
Share on other sites
7 hours ago, Gordon of Essex said:

I'll try leaving the cap off next time I'm away, although I'm doubtful about whether it'll help

 

 

It was just a thought.

Share this post


Link to post
Share on other sites

As you have eliminated the possibility of pressure build up in the flush tank it could possibly be leaking past a worn/damaged impeller on the flush water pump?  That’s the only connection between the flush tank and bowl so that would be my next thing to look at. 

 

Andy

Share this post


Link to post
Share on other sites

You say that it does not start to leak immediately.  Does it start after it has been flushed?  It could be that the anti-syphon vent is blocked.  There pipe from the pump should go above the water level before going down to the flush jet, with a small vent at the highest point.  If the vent is blocked then the water can syphon down from the tank to the pan. 

 

Share this post


Link to post
Share on other sites

Just a comment but no help with the problem. You do not need to use a pink solution, water on its own is good enough and avoids the perfume smell it can contain and maybe getting chemicals on your nether regions. Makes draining down easier as well since water can go on the floor.

Share this post


Link to post
Share on other sites
2 hours ago, Mr Plodd said:

As you have eliminated the possibility of pressure build up in the flush tank it could possibly be leaking past a worn/damaged impeller on the flush water pump?  That’s the only connection between the flush tank and bowl so that would be my next thing to look at. 

 

Andy

Thanks, I'll look into that.

Share this post


Link to post
Share on other sites
20 minutes ago, DACS said:

You say that it does not start to leak immediately.  Does it start after it has been flushed?  It could be that the anti-syphon vent is blocked.  There pipe from the pump should go above the water level before going down to the flush jet, with a small vent at the highest point.  If the vent is blocked then the water can syphon down from the tank to the pan. 

 

Thanks it's worth looking into although It doesn't necessarily start after it's been flushed. I have at least once filled it, checked it's OK then had to go out immediately only to find the pan half full when I get back. I didn't realise there was another vent, how hard is it to get to?

Share this post


Link to post
Share on other sites
9 hours ago, Gordon of Essex said:

Thanks it's worth looking into although It doesn't necessarily start after it's been flushed. I have at least once filled it, checked it's OK then had to go out immediately only to find the pan half full when I get back. I didn't realise there was another vent, how hard is it to get to?

The anti syphon valve would only have an effect if it occured after flushing, you would see a constant trickle when the pump has stopped, mentioned in my first reply.  When you say it's a screw cap is there an outer flap too? if the screwcap is vented but the flap isnt you could get the same result. Try leaving the flap open as well if fitted, the only way that I can think of for pressure to build up in there is by air heating and expanding forcing the water out. If it truly is vented that wont happen.

Share this post


Link to post
Share on other sites
11 hours ago, AJGalaxy2012 said:

The anti syphon valve would only have an effect if it occured after flushing, you would see a constant trickle when the pump has stopped, mentioned in my first reply.  When you say it's a screw cap is there an outer flap too? if the screwcap is vented but the flap isnt you could get the same result. Try leaving the flap open as well if fitted, the only way that I can think of for pressure to build up in there is by air heating and expanding forcing the water out. If it truly is vented that wont happen.

Yes there is a flap but I don't think it seals, I think I'll just try leaving the cap off to start with and see how that goes. I go away again end of August so I'll try then. Thanks for all your help.

Share this post


Link to post
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.


×
×
  • Create New...