f&e tank overflowing out to back yard

[Enda6]

Hello All could i please have some advise on this problem.

i have a twin coil cylinder in a bungalow, bottom coil for boiler, top coil for a rayburn stove (gravity feed on 24hrs a day) When i turn on central heating i get a steady trickle of water coming from the f&e overflow.

The ballcock is ok, warm water is coming from the hot tank ,through expansion pipe at top up into the f&e tank and eventually out into the overflow.
The bungalow is a new build and this has been happening from the very start.
My plumber told me to close off a vent pipe to stop it sucking in air but i am not convinced!What do you think?

 

[moggridgeplumbing]

Try turning pump speed down. Plumber saying block off vent pipe

 

[Enda6]

Try turning pump speed down. Plumber saying block off vent pipe

Thanks for quick reply. i will give it a go and let you know. I am a maintenance engineer by trade and this site is great reading. Im glad i found it!

 

[mysteryman]

This is indicative of a serious layout error, and it should not happen. Your system will be sludged up and rusty in no time.

Also, the boiler should be heating the upper coil, and the Rayburn the lower. Please refer also to the thread on unvented cylinders with uncontrolled heat input, if applicable.

Meanwhile, get the system sorted out without delay. No competent installer would fit such a system.

 

[Enda6]

This is indicative of a serious layout error, and it should not happen. Your system will be sludged up and rusty in no time.

Also, the boiler should be heating the upper coil, and the Rayburn the lower. Please refer also to the thread on unvented cylinders with uncontrolled heat input, if applicable.

Meanwhile, get the system sorted out without delay. No competent installer would fit such a system.

Thanks mysteryman i turned the pumps down to lowest setting and although the flow slowed it is still there. I am not a plumber but could you give me more detail on what you may think is wrong? I would like to be prepared for getting this sorted and would like to get my head around it. I also thought it would make more sense for the rayburn to heat the bottom coil as the primary heat source. I will be getting the plumber back to have it out with him!

 

[samthediyman]

1) Faulty ball valve
2) cross flow from mains water into central heating water
3) System is sludged up and needs power flush

 

[mysteryman]

There is a serious layout error of some sort. I can't tell you what it is, although you could post an accurate schematic of the system.

Don't accept any nonsense about this, the job has been botched.

 

[Mrmethane]

Hello

Your Rayburn is a combustion stove and therefore should be open to atmosphere and is a small circuit in it's self. So your flow pipe from your Rayburn rises up to your hot water cylinder coil, and possibly from there a expansion pipe will continue to rise into the roof space and terminate over your expansion tank. From the bottom of your tank a cold feed pipe should then connect to the return pipe to your Rayburn. This simple little gravity circuit is open vented and completely separate from your bottom coil circuit.

The circuit serving the bottom coil I take it is feed from a pressurised boiler which also serves your central heating radiators. If has you say the overflowing only occurs when the heating is switched on suggests that the systems are connected in some way and that is incorrect and needs to be attended to. Sealing the expansion pipe will effectively seal your system and turn it into a bomb.

 

[Enda6]

Hello

Your Rayburn is a combustion stove and therefore should be open to atmosphere and is a small circuit in it's self. So your flow pipe from your Rayburn rises up to your hot water cylinder coil, and possibly from there a expansion pipe will continue to rise into the roof space and terminate over your expansion tank. From the bottom of your tank a cold feed pipe should then connect to the return pipe to your Rayburn. This simple little gravity circuit is open vented and completely separate from your bottom coil circuit.

The circuit serving the bottom coil I take it is feed from a pressurised boiler which also serves your central heating radiators. If has you say the overflowing only occurs when the heating is switched on suggests that the systems are connected in some way and that is incorrect and needs to be attended to. Sealing the expansion pipe will effectively seal your system and turn it into a bomb.

You have perfectly described the system. I will try and trace the pipes and give you a better idea of the layout and see what you think. Thanks again