Hot Water Cylinder - Relocation to Loft

[mission impossible]

Hi

I'm undertaking a loft conversion and the airing cupboard/vertical cylinder gets the bullet to make way for the stair case. I've bought a horizontal cylinder (indirect/vented) that's going to live in the eaves but the question is, do I need to relocate the central heating pump, magnetic filter, two motorized valves (rads and underfloor heating) and air separator to the loft as well?

Strikes me that it would be easier just to run pipework on up to the loft for the cylinder coil and leave all the other bits where they are for easy access.

Also: must the cylinder bypass valve be physically located with the cylinder as well. Any good links to correct setting up would be appreciated.

 

[stem]

The pump and control valves don't have to be in the loft, however the domestic hot water feed and expansion tank will have to be located above the cylinder, as will the one for the boiler in order to pressurise the cylinder coil (unless you have a pressurised system or system boiler that doesn't have a F&E tank)

I assume also, that you will be having the loft conversion professionally done, so that the ceiling joists will receive the necessary strengthening to be able to take the weight.

 

[mission impossible]

Thanks stem

I'm doing the work myself but am following plans drawn by a grown up so joists will be able to take the weight. Ironically, since I posted, I've realized that I can't get a 1 meter head for the 50 gallon CWS so will have to rethink the project and relocate the existing cylinder under the new stairwell (unless there is any remedy for having the CWS and cylinder at the same level you can think of?).

Cheers,

Paul

 

[stem]

You can get rid of the CWS altogether with an unvented cylinder, the cylinder is pressurised by the cold mains, and expansion is taken care of by a pressure vessel. Have a look here, and scroll down to 'Unvented Hot Water Systems' for a schematic diagram.

 

[oldbuffer]

If you have suitable water pressure and flow rate you could consider going for an unvented hot water system. Hot water cylinder can be anywhere and the cold water storage cistern can go. However, you can't do it yourself, you need someone with the G3 qualification for unvented. Also you'll need to get it serviced by a G3 qualified person every year. Note that if the mains water goes off for any reason you'll have no hot or cold water until its back on.

 

[stem]

Or, go for a combi and get rid of all of the tanks in 'one fell swoop'

 

[mission impossible]

Thanks very much guys

I don't want to go with a combi because there's six of us in the house and we need the flow rate plus the old boiler is fine. Stem; that seems like a good idea on the unvented cylinder - I appreciate the link. Am I correct in assuming that's an option for domestic hot water whilst retaining the existing vented boiler system which is working fine (boiler in downstairs room and tank in loft) or does oldbuffer's point apply in any form of unvented hot water system (ie if I left the boiler side as is)?

With an unvented cylinder, would you/can you retain the CWS for domestic cold? Storage for this isn't an issue-just the head to the cylinder.

Cheers guys

 

[stem]

You are correct, the domestic hot water is heated by the boiler, and the hot water stored in a cylinder, but with a pressurised cylinder so you can lose the cold water storage tank. The boiler will still need its storage tank though, and it must be high enough to fill the coil inside the hot water cylinder which is connected to the boiler's circuit.

I'm not a combi lover, but in some circumstances, the advantages can outweigh the disadvantages and I thought this might be one of those occasions. Perhaps not.

If the CWS is used for domestic cold, yes you can just leave it as it is, or connect the domestic cold to the mains.

 

[mission impossible]

entered in error

 

[mission impossible]

Thanks Stem

Food for thought - I forgot to mention that I've got about 40M Sq Underfloor Heating downstairs so I think that would knock the combi on the head would it not? I can elevate the boiler tank without much trouble it's only 10 gallon (would 4 Gallon be ok). Suspending 50 gallons is something I'd rather not be getting into though

If I just go for the pressurized cylinder, do I need to go through a G3 qualified guy?

 

[Agile]

An unvented MUST be installed by a G3 qualified person.

A combi can feed a heating system. But it can only heat its rated flow rate of hot water usually about 9-13 li/min.

An unvented cylinder can provide up to about 24 li/min but that has to come from the mains supply so could be much less.

Tony

 

[Agile]

A CWS can supply about 20 li/min as well.


Tony

 

[mission impossible]

Thanks Tony