DIY Doctor UK DIY Forums

Hi All,

I am new to the forum, and am after a second opinion on what i think is a blocked coil in the hot water cylinder.

It started a few months back, after a bath was run in the evening the water would not get really hot again untill the next evening. It has gradually got to the point where it is only luke warm when running the hot water and is stone cold after running only half a bath. The primary flow to the cylinder (into the top of the coil) is fitted with a tapstat with a capillary tube inserted into the insulation of the cylinder, this seems to be ok and the pipe is very hot on the other side of the stat right up to the cylinder.

However, the pipe at the bottom on the outlet side of the cylinder is cold, the pipe is about 60cm long and connects back onto a 22mm T, the last 20cm of the pipe where it meets the T is very hot. The central heating is fine with all the rads piping hot.

My question is, if it is the coil blocked inside the cylinder, is it possible to rectify this and if so what would be the best method?


Thanks, Daniel

daniel foss,
The tapstat could have failed.
If the tank is old it may be full of limescale.
The primary pipework to the tank could be full of sludge.
end

"the pipe is about 60cm long and connects back onto a 22mm T, the last 20cm of the pipe where it meets the T is very hot."

There may be a clue here. Do you think there could be a blockage 20 cm from the T?

Firstly has any work been carried out on the system lately, radiators etc etc if so it could be airlocked.

Check the stat isn't faulty or turned down.

Are there any vents on the pipework to the cylnder, try opening these to see if there's air in the pipework.

How old is the cylinder ? it may be cheaper and easier to replace than trying to clear the blockage. It will definatley be cheaper than a powerflush.

Will watch for further posts.

htg

Thanks for all your replies guys, will get down and dirty with it the weekend and see what happens and will post my findings, probably from a life raft!

Thanks again, Daniel

Hi all,

Problem has been resolved, heating coil was airlocked, I fitted a bleed valve at the top of the coil in case I have this problem again. Great to have hot water again.


Cheers for now. Daniel