Intermittent Airlock

[Babybirddog]

Good afternoon, could do with some plumbing advice.

I have a rainwater harvesting system that feeds the utility room and the second en-suite toilets. It is indirect and the header tank is in the loft space above the utility room, (single storey about 2.2m ceiling height in that area).

The plumbing has been in use for about 2months and during that time i have had to clear an airlock in the pipe to the utility toilet about 4 times. This is fine for about 4 days, during which the en-suite also stops filling. I have checked the header tank which has its own control panel and this fills from the outside underground tank no problem. 

The washing machine feeds directly from the underground tank and has had no problems. 

The plumber has been less than helpful and is now on holiday for 2 weeks. 

Is the height of the header tank the problem, have only got this as the pump cycling is reduced and energy use is less but and can easily change the toilets to direct feed from the underground tank.

Any help much appreciated.

Thanks.

 

 

 

[PeterW]

A toilet fill valve needs a minimum pressure to work from memory - that could be your issue. 

[Temp]

+1

Some fill valves are supplied with pressure restrictors for use on mains pressure systems. Perhaps they left that in?

[Nickfromwales]

Hi.

If its air-locking, then does the pipe run flat or up & down, rather than continuously rise from each toilet back to the tank? With that little head available this will have quite an impact if the basics haven't been observed.  

[Babybirddog]

Thanks for the replies.

No, pressure restrictor not left in.

The pipe from the tank runs across the attic space 3m and then down the wall of the cupboard next to the toilet, the ensuite is a lot closer. I have no idea why the pipe was not put in 1st fix direct to toilet. Another question for the plumber. On closer inspection the pipework looks flipping awful. I have attached a picture of the pipe from the header tank (on the left)that goes up and over another pipe. Suspect this is part of the problem.

[PeterW]

Yep that’s the problem !

[Triassic]

The hump in the pipe on the right of the photo may be your problem. If there is a h7mp for n the pipe it will hold air and Hannover airlock. As said previously, the pipe should rise all the way back to the tank. If it falls at any point it will airlock.