What's happened to my toilet fill valves???

[TheMrX]

I'm stumped on this one...

About 1 year ago I installed two new toilets. (Different makes and models).

Yesterday evening, both would not fill after a flush. I have...

1. Checked the fill valve and theres just a very slow drip.
2. Checked the inlet pipe (after the isolator valve) and water is coming through fine.
3. Removed the fill valve completely, blown and hosed water through it to make sure it's not blocked.
4. Checked/removed the seal sets and cleaned them out.

But it's not made any difference.

The toilets are tank fed so pressure is not great, but both were fine for the past year, and I've made no changes to the plumbing at all.

Only thing I can do now is replace the fill valves, but before I do that can anyone offer any other advice.

Thanks in advance.

 

[Burnerman]

Curious that they should both fail at the same time, but there obviously isn't enough water pressure to lift the washers/seals of their seats. Is the header tank full?

 

[TheMrX]

Hi Burnerman

Yes header tank is completely full. The bath/shower takes a feed from the tank and although it goes via a pump it works fine. I've also switched off the pump and the water still comes through fine, but as mentioned that is on a separate feed from the tank.

Could it be due to some sort of air-lock?

It would be a lot of messing about but should I try connecting the mains feed to the sink to the toilet just to rule out fill valve problems? ie to see if it works under a greater pressure?

 

[joe-90]

Last time I saw this sort of thing a bit of loft insulation had fallen into the tank and blocked the feed hole. Put your hand in and have a rummage.

 

[TheMrX]

Well I checked the tank and it was nice and clean inside, no visible blockage at all.

Tested, the pressure coming into cistern and it was very low. Also noticed what looked like small pieces of limescale in the bucket used for collecting the water.

So, thinking there might be some sort of limescale build-up in the pipe I gave an almighty blow into the feed pipe. When the flow resumed it was about twice as powerful. Blew again and it was more powerful again, but then I reached a limit. This still wasnt enough to get a decent fill speed in the cistern so I then connected the fill pipe to the mains on the sink in order to back flush any possible obstacle in the way.
Result! When I tested again the pressure was perfect and fill valves are working perfectly again.

HOWEVER, I thought I'd check for views on this solution in case what I have done is storing up a bigger problem for the future.

Anyone have any definite views?

Thanks all.

 

[Burnerman]

A good result! I would reckon from your findings that there is a certain amount of limescale in your system, and I wouldn't mind betting that its the actual tank fitting - the outlet - that is the problem. Look for any solid chunks in the bottom of the tank and fish it out if its there. Chances are, the problem will come back at some time though unless you can physically remove the obstruction. Cheers John

 

[TheMrX]

Thanks for the reply Burnerman.

I thought I should check back in the tank, but having solved the problem I needed to get on with other things.

Will have a look over the next couple of days.