Expansion vessel position.

[echoes]

Hi all,

Just had a new boiler fitted (WB 24RI), and the gas installer positioned the expansion vessel on the flow just before the pump. The MI state that it should be on the return. It would be a trivial job to change this (once the weather is more clement!) but is it necessary, or better to just leave it as it is?

 

[onlyfitidealboilers]

should be fine the way it is, but worcester would not like it!

 

[lawrance]

I would seriously question the quality of the rest of the work of this clown.

 

[echoes]

Thanks... In every other respect it seems good: tee to vessel runs down from flow, and is nice and close to both boiler and pump.

I think I'll leave it be for now - I'll be re-siting the valve in the spring as part of having the towel warmer on the primary circuit any way, so could fix it at the same time.

 

[echoes]

I would seriously question the quality of the rest of the work of this clown.

Mmm - have already fixed the room stat wiring and identified a schoolboy error with the order of the returns causing reverse circulation when both HW + CH are calling at the same time... no cash has changed hands yet!

 

[Nige F]

I would seriously question the quality of the rest of the work of this clown.

How many clown like RGI`s actually read the MI`s Speaking as a fully paid up non gas clown , I thought the positioning of vessel was the norm - but then I don`t fit boilers so no need to read MI`s and no need to work either

 

[spraggo]

The EV should be connected to the system at a point close to the inlet side of the pump to maintain positive pressure through out the system.
It does not matter whether it is on the flow or return.

 

[slapper]

Allways fit mine on th return,dont likes valves restricting volume,on the return you should always have an open circuit,IMO

 

[spraggo]

Allways fit mine on th return,dont likes valves restricting volume,on the return you should always have an open circuit,IMO

Sorry I don`t get you there. Water can expand and contract back through the heat exchanger so whats the difference???.
Regards
spraggo

 

[picasso]

there are two reasons why it should be on the return, the diaphragm will last longer at lower temperatures and if its fitted on the flow the pressure from the pump will pressurise the expansion vessel and reduce its capacity for the expanding water,

and a very merry christmas to all

 

[spraggo]

there are two reasons why it should be on the return, the diaphragm will last longer at lower temperatures and if its fitted on the flow the pressure from the pump will pressurise the expansion vessel and reduce its capacity for the expanding water,

and a very merry christmas to all

Cheers and Merry Christmas to you piccasso, but I would like to point out that I suggested that the EV be fitted BEFORE the pump inlet, also that the EV is unlikely to get that hot as the water does not actually flow through it.

 

[picasso]

It does not matter whether it is on the flow or return.

Hi spraggo you were right with the ex vessel on the pump inlet but the above caught my eye care to comment ?

 

[spraggo]

It does not matter whether it is on the flow or return.

Hi spraggo you were right with the ex vessel on the pump inlet but the above caught my eye care to comment ?

Allways fit mine on th return,dont likes valves restricting volume,on the return you should always have an open circuit,IMO

Sorry I don`t get you there. Water can expand and contract back through the heat exchanger so whats the difference???.
Regards
spraggo

Hope this answers your query?
spraggo

 

[picasso]

Hi spraggo
and a merry christmas to you

 

[echoes]

Thanks all for your replies. I'm happy that the EV is as close to the pump inlet as it practically could be, and no valves or anything between the boiler flow and the EV (it's a conventional boiler). The EV does not get hot either.

I would be interested to know why the MI favour the return side though. Oh well....

Merry Christmas to you all!!