# Gushing and surging sound of water in pipes when water heating on in OFCH system



## Passport1 (21 Aug 2016)

Hi
I have and OFCH system

The timer is a dual timer where you can control the water and storage separately
Over last few weeks I have noticed that when the water heating is on that its very noisy in that you can hear the water rattling through the pipes and can hear a gushing or surging sound

Not using the storage/rad heating during the summer and just turning on the water heating on the timer when need hot water

Any thoughts on what could be wrong or how to fix it - could it be air trapped in the system ?

Thanks


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## Flyfisher (1 Sep 2016)

This sounds like air in the system. Not uncommon on oil heating systems. You may have sludge present in the pipework.


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## Páid (1 Sep 2016)

Did you bleed the radiators?


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## dub_nerd (1 Sep 2016)

Probably air in the system. Somewhere around the highest point of the system there will be a needle valve -- looks like a tiny tapered metal cylinder with a thumbscrew on top. Turn the screw and see if air escapes, any air should be followed by a few drops of water. Retighten finger tight. You may also need to top up the water in the system which will be a separate tap. There should also be a pressure meter either near the tap or near your boiler. A half to three quarters of a bar is usually about right.

Separately, you may need to bleed your radiators when you are going to use them again for the winter. This is similar to the needle valve procedure but you will need a key for the radiator valves -- you can buy one in Woodies. Again, loosen the valve until a drop of water comes out, then retighten. Don't worry if the water is dirty. If any significant amount of air comes out of your rads, then redo the needle valve / system top up.


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## Passport1 (4 Sep 2016)

Thanks very much for replies and suggestions. Bled the rads and there was fair bit build up of air in 2 of them. Since then the gurgling and surging has eased off. Going arrange get boiler serviced anyways before start using it more coming into winter.  Thanks for suggestions and help


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## Shane007 (5 Sep 2016)

I've often come across this, especially in bungalows where heating pipes travel through the attic space and drop down into the hot press and the system is open vented.

If so, the usual culprit is lack of static head. Basically, if you do not have 1/3 of the head of circulating pump between the water level in the f & e tank and the highest part of the circulatory system, each time the pump starts up, the water level in the open safety vent pipe will empty down into the flow pipe, bringing with it a gullop of air. When the system is on, it will sound like galloping horses through your heating pipes.

The fix, raise the f & e tank to above 1/3 of the head of the pump, so if you have a 6m head pump, the minimum distance between the circulatory pipework and the water level in the tank must be 2m.

Bleeding will only give you a limited reprisal of the symptoms as the noise will soon return as air is drawn into the system.


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