F and E tank overflowing

[CB3681]

Hi forum,

I have a regular vented system, F and E tank fed from the cold water tank, both of which are in the loft. Hot water is from a HWC in the airing cupboard on the first floor. The boiler is in the loft

I noticed a dripping from the F and E overflow (1 drip every 20 seconds), which got worse when the CH or HW (constant dripping). The ballcock valve is fine. I ran a magnet over the pipe work in the loft I could access, and found it sticking where the F and E joins the system. I used X400 to try to clear the blockage, but this didn’t work, so I cut out and replaced the pipe work. I used X100 when I refilled the system. All was well for two days when the dripping started again.

Obviously, water is getting into the system, and reading the many posts on here the likely suspect would be a holed coil in the HWC. However, my hot water from the tap is clear, and the F and E tank is higher than the CW tank by a good six foot.

I am absolutely baffled and would appreciate any suggestions as to what is causing this.

 

[HERTS P&D]

Post a picture looking into the F & E tank.

Andy

 

[Johntheo5]

If a heat only boiler post details/photos of circ pump while running + LEDs if a A rated pump.

 

[CB3681]

Hi John, not sure on the boiler being heat only, it feeds the CH system and the HWC if that helps.

We’ve only lived here for 6 months and the previous owners boarded the pump over in the loft. They have left a small access hatch that is a bugger to get off, but this only shows the top. I can’t see it being an A rated pump. If you think it helpful I’ll take the hatch off and take a pic, but not sure what you will get from it.

 

[Johntheo5]

You can see if its on speed 3, if so, reduce to speed 2.

Get someone to start the boiler and see if theres a spurt of water from the vent, then get the boiler stopped and see (you might have to wait for a few minutes pump overrun) if any spurt when the the boiler stops (zone valves shut) and then when the pump stops.

 

[CB3681]

Hi Andy,

F&E tank pic attached.

Hi Jon,

The pump was already set at 2. I’ve emptied some water from the image attached. No spurt when boiler turned on or off.

Thanks for the swift response both.

Chris

 

[Johntheo5]

What way is the vent and cold feed arranged?, from the boiler (flow pipe) and reasonably close to the pump there should be the Vent, cold feed then the pump, the cold feed and vent should be no more than 150mm apart.

 

[terryplumb]

The water level in the f&e tank is far too high. It only needs to be an inch or two above the outlet of the tank.
The level will raise when heating is on due to water expansion. Lower the level of water and see if it makes a difference.

 

[Johntheo5]

MIne is around a 1/3rd full when cold but only rises something like 15mm or less I seem to remember with all 10 rads fully hot. Its not alot anyway since 100l will only expand by less than 2L, dont forget the thimble full of expansion in the vent pipe.