expansion vessel

[jambo]

ok guys got a debate going on well more like an argument on an electric boiler in my opinion the expan vessel will go after the AAV on the flow the pump to rads but i have been told NO it goes on incoming cold mains someone help

 

[Dannypipe]

Why would it go on the incoming cold mains? It will be linked to the filling loop via the cold mains.

As for AAV, what about PRV?

I mean this in the kindest way possible, but a picture will paint a million words, and put you in the right direction.

 

[GQuigley67]

dont know much about electrical boilers, what I do know is that in unvented systems expansion vessel goes on cold mains supply !

 

[jambo]

sorry my fault the PRV and pressure gauge came with the vessel

 

[jambo]

would some one show me a pic or a link so i can shut this idiot up cheers guys

 

[Dannypipe]

Had a look and harder to find than I would have thought!

Right, as far as I know it should be like this:

On the return, linked to the Pressure Relief Valve, and the filling loop. With a pressure guage too.

I know they can be put on the flow though its bad practise for a few reasons. One the return water is cooler and will prolong the life of the rubber inside the vessel, and also you can have fluctuations in pressure and pump problems with it on the flow. I.E there can be a momentary pressure drop with it on the flow as the pump starts which may be enough to lock out the boiler. Though unlikely.

It should be on the negative side of the pump ideally.

Sorry I can't find a good picture for you.

 

[Dannypipe]

Expansion vessel, with PRV, guage and filling loop (with flexi hose detached)

Note the PRV isn't plumbed in either, but allows you to see common practise.

 

[jambo]

so pipe coming off back of vessel will be flow or return but what you said would be return correct cheers bud

 

[tamz]

It depends on what type of electric boiler you are on about.
An Amptec would just be like a std system. Nothing to do with water supply. Normally ev fitted on the flow before the pump. ((i know the arguments for fitting on the return and combi's and system boilers are fitted on the return but it is still before the pump).

An Electromax comes with everything built on, you dont need to do anything.

An electric combi like the Heatwell has 2. One on each.

A picture speaks a 1000 words, here

 

[Dannypipe]

On that pic the expansion vessel for the CH is on the return, as I have been saying.

 

[jambo]

its a heatrae sadia so tapped into flow and flexi to cold mains

 

[tamz]

On that pic the expansion vessel for the CH is on the return, as I have been saying.

So it is Danny, and on the wrong side of the pump too

 

[Dannypipe]

If in doubt mate, take a few pics, upload them. We'll take a look at it and set you right. As long as the PRV is installed correctly, then if it's wrong it will still be safe.

Cheers,

Danny

 

[tamz]

its a heatrae sadia so tapped into flow and flexi to cold mains

So it's an Electromax.
What are you'se arguing about then. It is built when it comes. Just fit it.

 

[jambo]

true true lets not pig