Gravity to fully pumped

[bowesie74]

I have an old oil boiler installed 45 years ago with two pipes going to the hot water cylinder. The other two pipes going to the radiators fed by a pump which is situated next to the boiler.
I have had four quotes to in stall a Worcester Danesmore 18/25 external oil boiler. Two claim that the new pump and zone valve can be fitted just inside the house where the new boiler pipes will come through.
The other two claim that there will have to be a new pipe installed from the loft area down through the house to the new boiler, this clearly will involve decorating costs. Who is correct?
Hope someone can help.

 

[denso13]

there will have to be a new pipe installed from the loft area

I doubt if that is required but without seeing the existing layout it is hard to be specific.

 

[ianmcd]

I am guessing but its just that a simple guess as you havent provided enough information, that you have a shared return for the HW and CH circuits in which case yes you would need another return pipe to achieve fully pumped individual control of both circuits, the fact that two companies have both mentioned that this is required would make me think that it probably is

 

[RickMoore]

+1 denso13. But to try and get to the bottom of it ask each installer why a new pipe is or isn't needed.
Last week I changed the inlaws 40 ish year old glowworm for a new vaillant. That was a similar arrangment with gravity Hw and pumped one pipe CH. Apart from removing the f+e pipework and altering the pipework at the boiler no alterations were needed. Took fookin ages to flush though lol
It is hard to say without actually seeing it though, either installer could be right.

 

[bowesie74]

This is the present set up, hope this helps.

Present set up

• bowesie74
• 15 Sep 2013
• 1

Hope this helps

 

[dcawkwell]

You can just put an external system boiler outside.
flow and return pipe go through wall and connect up to the existing pipes.
This would allow you to remove the central heating header tank
in the loft.
Job done. People do mess about. Sealed system is always the best for
a home installation. No messing it just works.

 

[bowesie74]

+1 denso13. But to try and get to the bottom of it ask each installer why a new pipe is or isn't needed.
Last week I changed the inlaws 40 ish year old glowworm for a new vaillant. That was a similar arrangment with gravity Hw and pumped one pipe CH. Apart from removing the f+e pipework and altering the pipework at the boiler no alterations were needed. Took fookin ages to flush though lol
It is hard to say without actually seeing it though, either installer could be right.

Just put more info on, this may help.

 

[bowesie74]

I am guessing but its just that a simple guess as you havent provided enough information, that you have a shared return for the HW and CH circuits in which case yes you would need another return pipe to achieve fully pumped individual control of both circuits, the fact that two companies have both mentioned that this is required would make me think that it probably is

Just put more info on this may clarify situation.

 

[bowesie74]

there will have to be a new pipe installed from the loft area

I doubt if that is required but without seeing the existing layout it is hard to be specific.

Just put more info on, this might help.

 

[denso13]

That's just a standard set up. The instructions say the feed and expansion pipework should be connected at the boiler, so fitting a new feed to the boiler, from the f&e cistern, could be the right approach.

 

[RickMoore]

That diagram dosent help much, it's not specific to your installation as is. Could be the vent pipe isn't piped correctly but only 2 spotted it.

 

[bowesie74]

I am guessing but its just that a simple guess as you havent provided enough information, that you have a shared return for the HW and CH circuits in which case yes you would need another return pipe to achieve fully pumped individual control of both circuits, the fact that two companies have both mentioned that this is required would make me think that it probably is

Just put more info on this may clarify situation.

My present system has two independent circuits one for the hot water cylinder and the other for the central heating, so there are four pipes coming out of the existing boiler, in the loft there are two tanks and the hot water cylinder.