Hot water tank boiling over

kraggy

hi folks,

every time i put on the heat (oil) for say more than 3 hours, the hot water tank in the attic boils over as i can see water coming down through the ceiling in my bedroom. when i run the hot water tap in the kitchen or bathroom this stops so it must be the heat making the water boil over.

anyone know what can be done to prevent this?

thanks a million,

k.

Qwerty?

The expansion pipe going up to the attic should be going into an expansion tank, check that it isn't missing its target... and check there is an overflow from the expansion tank, the extra water should be going outside if the tank is overflowing, not through your ceiling:eek:

crosstownk

Fit a thermostat to your water cylinder and a valve that will stop the heating system overheating your hot water.

Make sure that your immersion isn't on at the same time.

And as Qwerty? says - check the vent pipe from the hot water cylinder to the cold water storage tank. It's most likely pushed to one side a little or possible the cover of the storage tank has been shifted causing the water to run down the side of the tank.

kraggy

thanks guys, will check them.

JamesM

kraggy wrote:

hi folks,

every time i put on the heat (oil) for say more than 3 hours, the hot water tank in the attic boils over as i can see water coming down through the ceiling in my bedroom. when i run the hot water tap in the kitchen or bathroom this stops so it must be the heat making the water boil over.
anyone know what can be done to prevent this?
thanks a million,
k.

What hot water tank in the attic ? Is it the expansion tank for the heating ? It sounds as if the heating system is getting too hot. Is the boiler stat set too high, or not working ? It should be set at 60 to 70 degrees C. Does your heating cut in and out about every five mins or so, or does it run all the time.
Or are you talking about your hot water cylinder - could the immersion be on (and not cutting out) as well as the oil heating ?
Jim.

kraggy

hi jim,

as you can tell i'm not very diy minded.

after posting last night i went up into the attic and couldn't actually see a hot water tank! i thought there was one up there's water dripping through the ceiling occasionally when the heats been on for a while.

firstly, the temp of the heat is usually about 80 degrees. take it this is too hot from what you're saying but i didn't realise i couldn't have it up so high.

secondly, where is the water coming from? when the heat is on, the immersion gets hot. i just don't understand how a water system works! in the attic i can see a pipe come up from the immersion into the attic and hang open and over a tank in the immersion. is this in case the immersion boils over?

maybe it's this tank that's over flowing then and spilling water out on the floor of the attic and through the ceiling?

haven't a clue bout this sort of thing.
thanks

crosstownk

The 'immersion' tank is your hot water cylinder. Immersion refers to the electric element that is immersed in the water inside the hot water cylinder. The pipe that hangs over the cold water storage tank in the attic is indeed the expansion pipe for the hot water cylinder. I assume that this pipe is directly over the cold water tank and isn't spilling down the side or anything.

It could be that the overflow pipe for the cold water storage tank is blocked and if the hot water cylinder boils over when the cold water storage tank is full it could be causing the cold water to overflow.

Maybe it's time to sit in the attic and try to observe what is happening....bring some sandwiches

More info on domestic hot water here.

kraggy

thanks a million cross. makes perfect sense.

however, the overflow from the hot water cylinder is indeed directly over the cold water tank so it must be that the excess pipe for the latter is blocked or something.

will check later,

thanks again.

k.