F&E tank overflowing

[Beta]

I had a new hot water cylinder fitted last year, however, when it gets cold outside like it has done the last couple of days, there is a steady flow out of the hot water cylinder into the F&E tank in the loft that then overflows outside.

It only does this when its cold outside and has been fine over the summer. It did this a little last winter but I dropped the speed of the pump to speed II which seemed to fix it, however, this year, it's doing it again but only when cold outside.

If i draw off approx a washing up bowl of hot water off, then it stops.

Any ideas?

Is it possible the coil in the cylinder has split? If so, why would it only do it when it's cold outside?

Thanks

 

[dontknowitall]

Have a peek at this thread - I asked a very similar question recently and got some great replies ...

http://www.ukplumbersforums.co.uk/central-heating-forum/14512-hole-hot-water-cylinder-coil.html

Not saying your's has split but the responses indicate how you can tell if it has.

 

[Billy Bob Bob]

are you sure its the domestic tank over flowing? as altering the pump speed would have no bearing on this,if however its the heating tank overflowing there could be a few reasons

 

[ecowarm]

Very small pin hole in coil, made worse when cold because heatings on more

 

[Billy Bob Bob]

Very small pin hole in coil, made worse when cold because heatings on more

could be but unlikely on a year old cylinder, unless it was s/h

 

[Beta]

Was brand new, fitted in September 09. Believe its an RM cylinder looks like this RM Cylinders - Copper Vented Cylinders

 

[Billy Bob Bob]

rm sold by screwfix and toolstation,you need to get someone in as i said many reasons for this but i thbink we can eliminate the cylinder problems that can cause this are numerous,pump,boilerstat,cavitation,(pump speed) faulty immersion(if domestic f+e running) etc

 

[dontknowitall]

I'd try for a refund (plus cost of next installation) if it is a hole - should expect them to last at least 5 years. In fairness, Screwfix has been very fair on returns to me in the past so it might not turn out to be a major issue.

 

[Beta]

I don't have the receipt from screwfix as the plumber purchased (and i wouldn't have him back in my house - long story).
Will get another plumber in to take a look and see what the problem is.

Thanks all.