No pressure from the hot water tap

[Andrew Garrett]

Hi there
I live in an all electric flat with white meter heating.

The hot water system is in a cupboard and consists of a water tank with a copper cylinder underneath with an immersion heater. The water pressure for the cold tap is good but rubbish for the hot from every tap. We've changed the gate valve, had the tank out and cleaned out of silt and the pipe from the valve back to the gate is clear. Tomorrow I'm taking out the immersion heater and checking the pipe from the gate to the cylinder is not blocked. This looks like a simple system so what else could be the issue? Could it be an airlock somewhere - its a tiny flat and we've had this issue for a good few years but I've had enough it. It would take a week for fill a bath. I've had a plumber out for it but he's bamboozled by this. Its a howden We501 immersion heater driven system, not mains fed. There's a mains feed to the cold tap in the kitchen but the rest comes from the water tank.

thanks in advance

 

[ShaunCorbs]

sounds like a combined tank and cylinder

 

[Andrew Garrett]

probably the same characteristics as the above but 25 years old. Separate tank sits on a shelf with 2 28ml copper pipes coming out, one for cold with a gate valve to the bath room, and one with a gate valve to the boiler below which has he WE501 immersion heater

 

[ShaunCorbs]

distance between the two tanks?

 

[Andrew Garrett]

about half a foot. the system used to work fine. plumber has said that as the pressure from the cold is fine, there is no reason why the hot would be any different. we suspected a damaged gate valve which I've replaced but its made no difference. next we are checking from the gate valve to the boiler but cant really check from the top of the boiler out as we cant get to it. the immersion heater is a the bottom of the cylinder. the amount of labour this could potential cost is pointing me to just replacing the whole system as he can do this for around £750

 

[ShaunCorbs]

for what?

 

[Andrew Garrett]

supplying a fitting a 120 litre prostel unvented direct cylinder and getting rid of the old gravity fed system to make it mains

 

[Andrew Garrett]

else where on the forum it says that main cause of these symptoms is build up of scale inside the cylinder which blocks the cold inlet so i'll check tomorrow when I take the immersion heater out of the cylinder. is there some kind of acid I can use to dissolve this scale and clear the system?

 

[ShaunCorbs]

if you want a bath thats cylinders too small min i would install for a bath etc is 250l

is he g3 registered? (unvented qualified)

 

[ShaunCorbs]

else where on the forum it says that main cause of these symptoms is build up of scale inside the cylinder which blocks the cold inlet so i'll check tomorrow when I take the immersion heater out of the cylinder. is there some kind of acid I can use to dissolve this scale and clear the system?

best to scoop it out as it will / should be in chunks

 

[Andrew Garrett]

re: fitting a 250l tank

Bath facts. | Plumbers and Heating Engineers

 

[Andrew Garrett]

taking the immersion out tonight and seeing where I stand