Overfull F&E with a constant drip at outlet

[jimk280]

Hi all. Got a call out and discovered the Wilo 15-50 seized. replaced it. Went into the loft and noticed the F&E full to the overflow pipe which was on a rise! and so not overflowing at the outlet. I raised the F&E and the overflow outlet now has a constant drip. I initially thought the ballcock at fault but it's fine and is not leaking. I believe it must be expansion within the water heating that causes the level to rise above the ballcock but I'm not entirely sure. There is no auto-bypass fitted on the system.

I have tried the pump on all speed settings and it made no difference to the water level. I could raise the F&E on a platform but would that cure the problem?

A bit stumped on this and so could do with help if you've come across this.

Jim

 

[helpsy]

It's not that the coil in the cylinder has split possibly raising level in F&E.
Keep the F&E lower than the CWSC.
Maybe when the F&E was fitted they didn't allow for the 4% water expansion.

 

[justlead1]

Hi Bend the arm of the ball valve down. The cistern will then have a reduced water level and the distance between that and the overflow should accommodate the expanded water. However if this is not the case and the expansion cistern is below the cold water storage cistern it may well be a pin hole in the heating coil within the cylinderand the waters finding level.? Good Luck

 

[paul H]

sounds like the other guys have covered this but to make sure it is a faulty coil in the cylinder you could isolate the cold feed to the cylinder and see if the overflow stops ps you only need about 4" of water in the expansion tank

 

[jimk280]

Cheers for the advice guys, appreciated. Doesn't matter what I do with the ball valve height the water level in the F&E just rises above it. I hadn't though about a leaking coil but that kinda makes sense although I would expect unclean DHW wouldn't I? the F&E water was dirty and so was the pump when I changed it. I drained the F&E and refilled with clean when I changed the pump. Just a thought. Is there a dye I can add to the DHW in the CWSC? this would then transfer across to the heating water in the F&E if there were a leak in the coil?

regards

Jim

 

[REDSAW]

drain your heating system you will find it constantly continues to drip, eventually it will drain your cylinder too to a degree. then run some hot water into a glass and check colour clarity.

 

[jimk280]

Ok went to customers and switched heating on. CH & DHW cold. After 15 minutes the F&E overflow developed a steady drip as the CH flow reached temp. I turned off the gate valve from the CWSC to the DHW cylinder and drained the pressure through the kitchen hot tap. The drip stopped. The gate valve was then reopened and eventually the drip reappeared but as the DHW in the cylinder reached temperature the drip totally stopped. I'm sort of content that the primary coil within the cylinder has a hole in it? but why would the drip stop when the DHW within the cylinder is hot; any ideas?

Jim