Hot water in f+e overflow pipe constantly

[Azza41]

Hot water constantly dripping out overflow pipe. Changed mixer shower. Hot off cylinder via pump cold through mains with pev fitted. Pump fuse spurred to immersion socket. Customer thought it was constantly heating but still drips when off. Any ideas? Could water be backflowing from pev and up expansion pipe?

 

[Chuck]

I assume that you are dealing with a tradition vented DHW system with a cold water store feeding the cylinder and a feed/expansion tank in the roof for the heat system water?

If so, which 'overflow pipe' is constantly dripping? (Home owners sometimes identify them incorrectly so make sure.) Have you checked/replaced the float valve and ensured that the levels in the tanks are the correct amount below the overflow port?

 

[Azza41]

Yeah that's the correct system. Im on the presumption it's the f&e overflow system. Not yet returned to the job but I do know the tanks are in the smallest roof space in a dorma bungalow so access to check will be a nightmare and all the work was done off existing iso valves so the tank has not been touched nor the heating system other than turning off by the Electricion to connect the power up. Thanks

 

[Chuck]

I do know the tanks are in the smallest roof space in a dorma bungalow so access to check will be a nightmare

Like those adverts used to say:

Replace the float valve washer, £5
Scaffolding and roofer to gain access by removing tiles, etc. £500
Expression on homeowner's face when you give them the estimate: Priceless.

 

[Azza41]

Like those adverts used to say:

Replace the float valve washer, £5
Scaffolding and roofer to gain access by removing tiles, etc. £500
Expression on homeowner's face when you give them the estimate: Priceless.

Surely the water shouldn't be hot so how can it be the ball valve?

 

[Chuck]

Surely the water shouldn't be hot so how can it be the ball valve?

If water is "constantly dripping" out of an overflow that is connected to the F+E tank then in my experience there is a good chance the ball valve has failed because if it were working it would have shut-off tight be with the level safely below the overflow port.

It is normal for the water in the F+E to be warm but if it's really hot then presumably the system has been pumping over. The hot water in the F+E tank could be the root cause of the float valve failing or they could be independent of one another.

Or maybe the overflow is not connected to the F+E tank and the problem lies elsewhere.

If you're not confident and trained for this sort of work, get an experienced plumber involved. Mistakes can be costly and, you never know, if they like the standard of your normal work they might repay the favour and sub some work your way in return.

 

[Azza41]

If water is "constantly dripping" out of an overflow that is connected to the F+E tank then in my experience there is a good chance the ball valve has failed because if it were working it would have shut-off tight be with the level safely below the overflow port.

It is normal for the water in the F+E to be warm but if it's really hot then presumably the system has been pumping over. The hot water in the F+E tank could be the root cause of the float valve failing or they could be independent of one another.

Or maybe the overflow is not connected to the F+E tank and the problem lies elsewhere.

If you're not confident and trained for this sort of work, get an experienced plumber involved. Mistakes can be costly and, you never know, if they like the standard of your normal work they might repay the favour and sub some work your way in return.

Ibwas

If water is "constantly dripping" out of an overflow that is connected to the F+E tank then in my experience there is a good chance the ball valve has failed because if it were working it would have shut-off tight be with the level safely below the overflow port.

It is normal for the water in the F+E to be warm but if it's really hot then presumably the system has been pumping over. The hot water in the F+E tank could be the root cause of the float valve failing or they could be independent of one another.

Or maybe the overflow is not connected to the F+E tank and the problem lies elsewhere.

If you're not confident and trained for this sort of work, get an experienced plumber involved. Mistakes can be costly and, you never know, if they like the standard of your normal work they might repay the favour and sub some work your way in return.

Thank you for your response I was mainly questioning if anyone had had any issues after fitting pev's with the water backfilling.

 

[Azza41]

Ibwas

Thank you for your response I was mainly questioning if anyone had had any issues after fitting pev's with the water backfilling.

Because its not my issue if its not related to my work

 

[John.g]

Assuming its overflowing from the F&E tank then,
If a vented HW cylinder is installed and the CWST is higher than the F&E tank
then a split coil can account for the above, a unvented cylinder can do likewise.
Suggest reducing the CWST level to below the F&E tank level and see if the overflowing stops?.

 

[Azza41]

Assuming its overflowing from the F&E tank then,
If a vented HW cylinder is installed and the CWST is higher than the F&E tank
then a split coil can account for the above, a unvented cylinder can do likewise.
Suggest reducing the CWST level to below the F&E tank level and

Thanks. So realistically other than an unbalanced shower mixer it won't be anything I've caused

 

[John.g]

Can't see how a unbalanced shower mixer can cause any problems for the heating system as it is a completely separate system.

 

[Azza41]

Can't see how a unbalanced shower mixer can cause any problems for the heating system as it is a completely se

Can't see how a unbalanced shower mixer can cause any problems for the heating system as it is a completely separate system.

Im only under the assumption its the f&e tank I'm thinking the cold is pushing the hotvwater up the expansion pipe into the header tank

 

[John.g]

It could possibly push hot water into the cold water storage (CWST) tank but no way into the F&E tank, just establish which tank is overflowing.