Hot water cylinder spec?

[Andrew 03]

Hi Folks,
I've got a leaking cylinder. It is gravity fed. Do i need the heat exchanger to be 28mm?? If yes, are they easy to get hold off? I understand screwfix cylinders are for pump fed systems only - i assume this is becuase the heat exhchangers are narrower pipe?

I'm still trying to find where exactly the leak is - it's around the cold water inlet, but the insulation makes it difficult to find, and i don't want to investigate too much until i've time to sort it out completely.

Many thanks
Andrew

 

[Gray0689]

Just get a good local plumber to change it mate

 

[Andrew 03]

THanks for the suggestion, but i'm curious what tanks needed - and can't find the info on the web. A friend has told me i need a 28mm heat exchanger, and these aren't common. I'm thinking if they are expensive, is it a good reason to change to a pumped system which an ordinary cylinder would be fine for, and would probaly be a better system than gravity fed - or can i get a cheap quick replacement cylinder that works on gravity fed?
Cheers
Andrew

 

[washer]

Gravity hot water just requires 28mm pipe going to the cylinder, which you would already have i assume, any indirect copper cylinder will do.

The plumber you use will have the necessary 28mm fittings, changing to a fully pumped system would be better, but cost quite a bit more cash.

 

[ron swift]

Re: Hot water cylinder spec

I have a similar problem.Pumped systems appear to have a 22mm coil, which i am advised by RM Cylinders tech. dept. will result in air locks if used with a gravity system.I believe that you are correct that you need a 28mm coil.I hope to source one too.Any help appreciated.

 

[kirkgas]

you also need to pick the correct grade of cylinder, grade 1, 2 or 3 depends on the head of pressure between the tank in loft and the cylinder, grade 3 is the weakest (for the shortest height)

 

[WHPES]

Change to pumped system - far more efficient.

Otherwise your cylinder must be for gravity systems and stated as such (the majority aren't). I have seen so called professional plumbers fit cylinders unsuitable for gravity onto gravity systems so beware!