Central heating pump in airing cipboard.

[ARTICIFER]

My airing cupboard which houses the hot water storage tank is situated directly above the floor standing boiler which is in the kitchen. I want to shift the pump and mid port valve from its present position, adjacent to the boiler, to the airing cupboard. The aim is to allow easier access, reduce the amount of kit adjacent to the boiler and minimise the number of pipes between kitchen and airing cupboard.

The feed and expansion pipes will be combined between the airing cupboard and the kitchen, which I believe is a common arrangement. What should I do with the return pipes though? Can these be connected together in the airing cupboard with a single pipe to the boiler or must they both be routed back to the boiler and teed there? The CH pipes are all run between ground floor ceiling and first floor floor, so teeing the returns together in the airing cupboard would be easy to do. There would then be only two pipes (flow and return) twixt kitchen and airing cupboard.

Thanks for any advice.

 

[D_Hailsham]

The feed and expansion pipes will be combined between the airing cupboard and the kitchen, which I believe is a common arrangement.

Which make/model boiler do you have? You need to check that a combined feed and vent pipe is approved by the manufacturer.

What should I do with the return pipes though? Can these be connected together in the airing cupboard with a single pipe to the boiler or must they both be routed back to the boiler and teed there?

No reason why you can't do that. The important thing is that the return from the HW cylinder must be the last connection, i.e after any rad Tees and nearest to the boiler.

The vertical distance be between the pump and the water level in the F/E tank must be at least 1.4m. The pump should be either in a vertical pipe pumping upwards or in a horizontal pipe. If in a horizontal pipe, make sure that the pump shaft is horizontal or slightly higher at the vent end to prevent wear on the bearings.

 

[ARTICIFER]

Thanks for your reply.

The boiler is an Ideal Mexico HE15 and according to the spec combined F&E is allowed. I can meet the conditions regarding 1.4m vertical head and the position of the HW tank return.

I'm a bit confused by "pumping upwards". Does this simply mean that the pump outlet must be above the inlet?

I can mount the pump either vertically, with the outlet at the top, or horizontally. The outlet pipes would then have to be routed downwards from the diverter into the HW coil and CH. The only way I'd be able arrange things so that the pipe from the diverter to the HW coil is routed upwards would be by raising the cylinder on a platform. The pipe from the diverter to the CH will have to be routed downwards.

 

[D_Hailsham]

The boiler is an Ideal Mexico HE15 and according to the spec combined F&E is allowed.

OK, but why do you want to do this?

I'm a bit confused by "pumping upwards". Does this simply mean that the pump outlet must be above the inlet?

Yes. The pump has an arrow on the body showing direction of flow. The arrow should point up.

I can mount the pump either vertically, with the outlet at the top, or horizontally. The outlet pipes would then have to be routed downwards from the diverter into the HW coil and CH. The only way I'd be able arrange things so that the pipe from the diverter to the HW coil is routed upwards would be by raising the cylinder on a platform. The pipe from the diverter to the CH will have to be routed downwards.

Now it's my turn to be confused. What do you mean by then? Are you talking about when the pump is vertical or when it is horizontal?

Having the pump horizontal is perfectly acceptable if that is easier, provided you make sure the shaft is horizontal or slightly higher at the silver vent plug end.

 

[ARTICIFER]

I have probably used the term "Combined F&E" incorrectly. I will try to explain what I am planning to do.

The current boiler was professionally installed to replace a 40 year old system boiler with integral pump for the CH. The old boiler had four connections and used gravity to circulate boiler water through the cylinder coil in 28mm pipes. The new boiler uses the existing pipe work fed through an external pump and midport valve. Extra pipes were routed to the boiler area for F&E, the old F&E went directly to the HW cylinder coil and have been removed. So I now have seven pipes between kitchen and airing cupboard, namely F, E, CH Flow, CH Return, HW Tank Flow, HW Tank Return and Hot Water to the kitchen taps. The whole thing is a mess with some pipes half buried in the plaster and showing signs of corrosion. The pipes take up a lot of space and I doubt it will be possible to remove the pump easily as there isn't room to move a spanner by even 1/12th turn. It's sitting at the back of a space barely wider than itself.

I plan to move the point at which the F, E and flow pipes meet to the airing cupboard reducing the number of pipes between kitchen and airing cupboard to three. The F and E would still be separate pipes, but they would be about eight feet shorter. There will be 8 feet long 22mm flow and return pipes twixt kitchen and airing cupboard. Apart from that the piping will be just like the nice diagrams in boiler installation manuals


I can mount the pump either vertically with the arrow pointing upwards, or horizontally. If I mount it horizontally I will make sure the vent plug end is raised slightly. However no matter how I mount the pump its outlet will be above the inlet to the cylinder coil and above the pipe serving the radiators. Thus the pipes from the mid port valve will have to be routed downwards. I'm unsure as to whether this constitutes pumping upwards or not.

 

[D_Hailsham]

I have probably used the term "Combined F&E" incorrectly. I will try to explain what I am planning to do.

OK I see what you are proposing: Flow pipe from boiler to airing cupboard; separate feed and vent pipes; pump; mid position valve (branch to HW & branch to rads). Return from airing cupboard to boiler.

The HW pipe to the kitchen is irrelevant - you can't do much about it.

However no matter how I mount the pump its outlet will be above the inlet to the cylinder coil and above the pipe serving the radiators. Thus the pipes from the mid port valve will have to be routed downwards. I'm unsure as to whether this constitutes pumping upwards or not.

That's no problem it's only the pump itself which is important.

It sounds as if it will be easier to mount the pump horizontal, if so the feed and vent pipes can also be connected into the horizontal feed pipe before the pump, like this:

Feed and Vent

• D_Hailsham
• 17 Oct 2010
• 1

 

[ARTICIFER]

Thanks.

That makes everything perfectly clear to me.