Small Header Tank Overflowing

GFunk Step2 This · 29-02-2024 6:00pm #1

Does anyone know why the central heating header tank could be filling up.

It seems to be filling up from the pipe that feeds to the oil boiler (Initially thought it was the ball valve but its been replaced and issue persists).

It happens shortly after I turn on the central heating. Plumber reckons it could be the that the coil is gone in the cylinder.

We had a condensing oil boiler installed over a year ago - could it be something to do with that?

Not sure exactly how long its been going on as only noticed recently.

Any help is appreciated!

G

declan b · 01-03-2024 12:30am

it could be the coil or it could be pitching. Tie up the ball valve and monitor the level daily and see what you get

declan b · 01-03-2024 1:22am

how many inches of water is in the header tank when heating system is cold...., also how many inches is the water in the header tank from the overflow pipe when system is cold

tb66 · 01-03-2024 1:54am

When you say filling up from overflow pipe, do you mean the pipe thats above the small header tank and when heating is on its over pumping/pitching. Have you changed the pump settings recently? Like from no 2 to 3.? If coil is leaking you should have option to isolate it. Have you a Zone valve fitted to allow either heating/hot water? Maybe even a gate valve if it an old system. You can manually turn zone valve too.Turn that off and see if problem persists.

GFunk Step2 This · 01-03-2024 5:57pm

Thank you for the replies.

The water level is very high in the tank. Sits just below the overflow level when the heating is off. When I turn the heating on the water seems to come backwards into the tank from the Feed Pipe. And then obviously overflows and spills out of the roof.

I even emptied out the tank halfway and within a day it was filled up again - and not from the ball valve.

I'm thinking that maybe the coil has a hole because how else would all this excess water get in the system?

But then if the coil has a hole would the water be overflowing constantly and not just when the heating is on?

What is pitching exactly?

GFunk Step2 This · 01-03-2024 6:02pm

image if it helps

declan b · 01-03-2024 8:09pm

Normally there was a pin hole in coil the water should rise up to overflow even when heating system.

i would set the level in the tank to 100mm from bottom of tank when the heating system is cold.

Also as tb66 said . check what setting the circulating pump is on

tb66 · 02-03-2024 2:53am

https://www.boards.ie/discussion/comment/121838541#Comment_121838541

Just to be sure what were looking at. The pic is the small tank in attic, not the the big one. Pitching/overpumping means your circulating pump is either on too high a setting or have a blockage and water is being dumped back in header tank. Are you sure the the tank is is being filled from the outlet and not the expansion pipe. If this is the small tank and you have an open vented system there there should be another pipe over that tank. If your coil had a leak the extra water could end up either out you cylinder expansion pipe or you circulating pump could be sucking it in and sending it to your heating expansion tank which defo explain your problem. If you have zone valve for hot water either use your electric controller to turn it off or manually turn it off and check you tank level then.

Lenar3556 · 02-03-2024 8:49am

https://www.boards.ie/discussion/comment/121838541#Comment_121838541

The expansion tank is too full for a start. The ball cock arm needs to be bent downwards (two vice grips might be helpful). As suggested by others, 4” at the bottom when the system is cold is lots.

After that reassess if you still have an overfilling issue. If so a leaking cylinder coil is probably the cause.