is my hot water gravity?

[lorme86653]

Hi everyone,

I'm trying to improve my inefficient, hard to control Central heating system. But to do so, I need to fully understand it first, and something has stumped me:
I have a vented cylinder system (1 tank in the loft), heated by a Rayburn gas oven/boiler. I would expect my hot water to be gravity fed, but some how it is mains pressure (turning off stop chock stops hot water)??


Anyone know how this might work? Crude drawing attached.

 

[JohnD]

What colour is your cylinder?

photos would help.

 

[lorme86653]

Thanks for getting back, I can only see the yellow insulation. Pics attached.

 

[gasmanstu72]

1 tank in the loft would suggest you have a primatic cylinder.

EDIT: just seen your pictures, ignore this. unless you want to know how a primatic cylinder works

 

[ianmcd]

That is a Tribune, mains pressure cylinder, not a gravity cylinder

 

[lorme86653]

Thanks, that clears that up, so in the image attached, where would the mains pressure come from for the cylinder? And what is the loft tanks purpose?

 

[muggles]

Thanks, that clears that up, so in the image attached, where would the mains pressure come from for the cylinder? And what is the loft tanks purpose?

That image isn't relevant to your system. The mains pressure comes from the mains water supply. The tank in your loft feeds your heating system with water, and takes up expansion as it heats

 

[lorme86653]

Thanks everyone for your help, this also explains why there's a separate pump for the central heating.

I did think it was a primatic cylinder, which has put me off using cleaners and inhibitors in the past, happy I can now add some treatment.