Dangerous Plumbing PLEASE HELP ASAP

[BigDave82]

Hi everyone, I have been using this website for a good while now and find its great advice. Now I need some really great advice!

I have been looking into fitting a boiler stove to run central heating and my hot water as I already had an open fire which feeds my hot water cylinder. I am hoping to do the install myself and so have been looking at my existing plumbing and have found to the best of my floor board lifting capabilities that there is NO vent or cold water feed to the boiler!!!! It seems to be a sealed gravity fed system that in my opinion cold very well explode with super heated water killing me and my family! Ok drama over but I will need to sort this ASAP help with links to diagrams would be fantastic.

[plumbbob]

Are you saying there is no header tank? Does the system have an expansion vessel? Does the hot water have a header tank? IS there evidence of anything that looks like a safety valve?

Before you panic, more information is really required.

[BigDave82]

There is no header tank, no expansion tank and no PRV. It seams to be a sealed circuit with a furnace at the bottom!

There is a header tank for the Hot water within the cylinder but nothing for the water heating the cylinder

[plumbbob]

It seams to be a sealed circuit with a furnace at the bottom!

Can't be sealed without any provision for the expanding water. The pipework would have failed the first time the fire was lit.

There is a header tank for the Hot water within the cylinder but nothing for the water heating the cylinder

My guess is the heating circuit shares a common feed from the one header tank as was often the case in earlier systems or the whole system is only a single circuit. This was the norm prior to full central heating systems.

[BigDave82]

I cant find anywhere there could be a tee off, I can trace the pipes from the boiler to the tank without interruption. Unless there is something within the hot water tank or boiler itself then there is nowhere for water expansion. Do you have any old diagrams etc?

[plumbbob]

This an old diagram I have found of a 1970's hot water system. The tank is considered "direct" ie, the hot water and heating circuit are not separated.

Pay particular attention to how the heating circuit connects to the cylinder. In an indirect system (two circuits), the in and out connections are close together about a third of the way up the cylinder. In a direct tank, the in and out are much closer to the top and bottom of the cylinder making them much further apart.

[bobtb007]

Hi Dave

The system you have may be a fortic type utilising a "combination" cylinder, have a look here

http://www.range-cylinders.co.uk/pdfs/sales/copper.pdf

Some of them are made so that the header tank is not easily identifiable as in here

http://www.telford-group.com/Products/v ... tCombi.asp

As for running your heating system from your solid fuel burner then you will need to put in a complete "secondary" actually primary circuit to serve the rads, complete with two or three port valve connected to a cylinder thermostat, a pump etc and you need to make sure that the cold feed and vent pipes are properly connected to prevent what you are fearing may happen.

For my money, best bet is to get in a competent plumber/designer to do your design pay him for that service and then install yourself

Hope this helps

Russ