F+E tank filling with hot water

[IanPlumber]

Hi all,
I am having a problem at home. Over the last few days my f+e tank has been filling with hot water.
I have tried several things but nothing has cured it.
I think i have now ruled out a cylinder problem but am unsure.
What is the easiest way of telling if this is the case?
So far I have shut off the cold supply from my storage tank to the cylinder and ran the hot taps for a while until the water stopped. The F+E tank did not fill or empty.
It says on a sticker on the side of the cylinder " ???crificial cylinder with anode" (first part of the sticker is missing). Also it says on another sticker "Churchill 1.5hr recovery with gravity".
Not quite sure how these work inside so if anyone can enlighten me i would appreciate it.
The F+R to the cylinder are 28mm and there is a 22mm pipe from the return going to the F+E tank with the expansion pipe off of that.
The cylinder does not have a stat as far as i can see and i can't find a zone valve anywhere.
The F+E tank seems to fill via the expansion pipe at random times. It is not the supply letting by as i have checked that.
The boiler is making noises similar tapping or bubbling (best i can describe it).
Can someone enlighten me as to how an already filled system can dump so much hot water back into the F+E tank.
Please help as i am starting to run out of ideas here.

 

[seco services]

is it the heating f/e filling (the little tank) or the cws tank filling from the vent pipe ?

 

[IanPlumber]

Hi,
It's the F+E thats filling. I have raised the vent pipe so it's about 400mm above before descending into the tank.
I could understand if it was a constant fill but it seems to be a surge of water being dumped into the F+E ever so often. My neighbors have been telling me all of this info as i am at work during the day and have only been playing around with it in the evening time.

 

[seco services]

need to know if the cws is refilling at the same time the f/e vent is filling the tank. if so poss your coil in the cylinder is holed.

you say your boiler is bagging and tapping. could be pumping over.
which is where your boiler stat can be faulty, so running very hot and boiling the water, or a blockage in system etc

 

[IanPlumber]

Hi,
Im really not convinced that it is my cylinder but the pumping over seems more likely, I just don't understand where the water is coming from to over flow? Is this because the water is expanding so much due to temperature.
Is the stat you are talking about the boiler stat or room stat?, I'm taking that it must be the boiler stat as i have checked the room stat and it appears to work fine.
I will drain down the system this weekend and back fill it to see if there is a blockage.
Any more clues?

 

[seco services]

yes like a kettle half fill it and boil it. water level raises quite abit.

boiler stat, check where it is set to then run the boiler and turn the stat down you'll hear it click and shut off boiler then turn it back up boiler will restart.

sounds like you have pumped heating and gravity water and no cylinder stat.
i would go for a blockage.

 

[IanPlumber]

Hi,
I have an old Ideal back boiler. The boiler stat turns the boiler on and off fine.
I do have pump heating and gravity water with no cyl stat.
Can you explain to me why you think it's a blockage please.
Thanks

 

[seco services]

yes that is the stat. what is it set to ?
does it shut the boiler off when you turn it down ?

just a guess but i've seen so many like yours that have the same problem and been a blockage.
what is the bottom of the f/e like ? has it a layer of sludge or silt or clean ?

 

[IanPlumber]

Hi,
A small amount of slit at the bottom of the tank.
The boiler stat does turn on and off the boiler. It's set on No.5 (out of 0-6 dial).
If i turn the boiler down to No. 4 it gets cold in the house.
Thanks

 

[seco services]

what is the pump set to ?

 

[IanPlumber]

The pump was on 2, Now on 1.

 

[seco services]

and it vented at 2 does it vent at 1?

 

[IanPlumber]

Hi,
So far it has not dumped any water into the F+E but it may be too early to tell.

 

[seco services]

yes i still go for a parshal blockage.
while it's set low and not venting i would try some sludge remover in system and let it run for a while then drain the system and refill with clean water.

 

[IanPlumber]

What would you suggest as a decent cleaner? Is sentinel X400 a good one?