Reasons why F & E overflows?

[poolebybirth]

apart from a faulty float valve letting water by, or a hole in the float ball preventing the float arm rising and shutting off the supply, and a pinhole in the hot water cylinder coil, what other reasons are there for a Feed & Expanison tank overflowing?

 

[nickso]

constantly overflowing?

could be a shower backfilling the cylinder.

 

[poolebybirth]

why would a shower backfill the F & E?

 

[seco services]

it wouldn't

 

[poolebybirth]

if anything it would be the cold water tank. NOT the f & e.

 

[nickso]

my mistake. i skipped over it when i read hot water cylinder.

 

[powell30]

blockage in heating pipework. Pinholed coil as mentioned.

 

[BournemouthPlumber]

Agree with powell30. 9/10 times blockage is where cold feed from F&E joins on to return pipework.

Can clear with gently tapping of pipework to dislodge anything there, magnets either side to try and sift a blockage, try tipping down kind of pipe clearing solution down the outlet from the F&E if thats possible. Alternatively can try and cut out the blocked section and replace - but be careful when doing this as the blockage may be preventing the system from draining down correctly and when you cut into the pipework you may get drowned Might be best if you are going to go that route to freeze the pipes you want to cut out.

 

[twgas]

have seen overflow from cws terminating over f&e and causing that to overflow to outside. would be fairly obvious though.

 

[poolebybirth]

usually the cold feed joins the boiler (primary) flow pipe - if close coupled which mostly systems are.

 

[seco services]

which causes water to go up the vent pipe if blocked.