expansion tank overflow

scas100

hi, i couldnt find this exact problem on here - the small expansion tank for the heating system is overflowing out the pipe at about a drip per second. i changed the ballcock and it made no difference, so i changed it again-nothing and then bent the arm to make it lower-still the same problem.
the thing is theres no dripping from the sort off upside down hockey stick shaped overflow pipe that sits above the expansion tank, and also at this stage ive had the heating off for 2 days, without turning on the immersion heater (i dont know if thats related at all ) and still, drip drip.
the boiler tank is only about 3 years old as well.
any suggestions?

Spook_ie

scas100 wrote: »

hi, i couldnt find this exact problem on here - the small expansion tank for the heating system is overflowing out the pipe at about a drip per second. i changed the ballcock and it made no difference, so i changed it again-nothing and then bent the arm to make it lower-still the same problem.
the thing is theres no dripping from the sort off upside down hockey stick shaped overflow pipe that sits above the expansion tank, and also at this stage ive had the heating off for 2 days, without turning on the immersion heater (i dont know if thats related at all ) and still, drip drip.
the boiler tank is only about 3 years old as well.
any suggestions?

From description, only 2 places water can get in, fill pipe with ballcock or reversed flow from the outlet, had a similar problem which was the indirect heating coils in the hot tank being corroded and water transferring from cold tank to heating overflow by siphoning.


First thing in morning or after a period of the house being empty check if the cold storage tank is being fed at a similar rate , if it is there's your answer.

https://touch.boards.ie/thread/post/106792777

Wearb

scas100 wrote: »

hi, i couldnt find this exact problem on here - the small expansion tank for the heating system is overflowing out the pipe at about a drip per second. i changed the ballcock and it made no difference, so i changed it again-nothing and then bent the arm to make it lower-still the same problem.
the thing is theres no dripping from the sort off upside down hockey stick shaped overflow pipe that sits above the expansion tank, and also at this stage ive had the heating off for 2 days, without turning on the immersion heater (i dont know if thats related at all ) and still, drip drip.
the boiler tank is only about 3 years old as well.
any suggestions?

How does the water surface level (not its height from the top of the tank, but as if you were to put a long spirit level on the surface of each) in the expansion tank compare to the larger tank?

Spook_ie

Spook_ie wrote: »

From description, only 2 places water can get in, fill pipe with ballcock or reversed flow from the outlet, had a similar problem which was the indirect heating coils in the hot tank being corroded and water transferring from cold tank to heating overflow by siphoning.


First thing in morning or after a period of the house being empty check if the cold storage tank is being fed at a similar rate , if it is there's your answer.

https://touch.boards.ie/thread/post/106792777

Checking should be done while no one is likely to be running water off taps or flushing loos etc. to make it easier to spot a slow drip.

scas100

Wearb wrote: »

How does the water surface level (not its height from the top of the tank, but as if you were to put a long spirit level on the surface of each) in the expansion tank compare to the larger tank?

the water surface of the big tank is about a foot higher that the water surface of the little tank

scas100

i just changed the ballcock to the bigger tank while i was up there and drained the little tank of excess water to get it down to normal-so it wont be dripping for a while.


so im guessing if it starts again im looking at another new hot water tank :eek:

Wearb

scas100 wrote: »

the water surface of the big tank is about a foot higher that the water surface of the little tank

When it starts dripping again, get the level in the big tank lower than surface level in small tank. It will mean tying up ballcock or turning off a valve and running a bath tap or wash basin.

If it stops then, I’m afraid it’s another cylinder. Perhaps you Plummer could diagnose the cause of it going so soon.

scas100

Wearb wrote: »

When it starts dripping again, get the level in the big tank lower than surface level in small tank. It will mean tying up ballcock or turning off a valve and running a bath tap or wash basin.

If it stops then, I’m afraid it’s another cylinder. Perhaps you Plummer could diagnose the cause of it going so soon.

i will try that later, probably a poorly made oriental cylinder-thanks