C-Plan System boiler and tank location

[Straiton70]

Hi,

My daughter has just purchased a house with a C-Plan boiler system installed. The boiler and tank used to be next to each other in cupboard, but the pervious owner has moved the boiler to the loft.

My understanding is that the hot water works on a gravity feed, but with the boiler in the loft and the tank in the downstairs cupboard and no pump. How does the water circulate when the boiler is higher than the tank?

Thanks

John

 

[MNW67]

It depends what you mean by a gravity feed. Do you mean the hot water in the cylinder, which goes to the taps, is fed by gravity from a cold water tank?

Or do you mean the hot water in the cylinder, is heated by gravity, from the boiler?

When you mention a tank in the cupboard, do you mean a hot water cylinder or a cold water storage tank? Which floor is that tank/cylinder on?

 

[Hugh Jaleak]

Hot water supply to taps may be on a gravity feed, i.e. there is a Cold Water Storage Cistern above the Cylinder somewhere, which feeds the cylinder which in turn feeds the Hot Water Taps.

The water circulating through the boiler and Radiators, will also probably be used to heat the Cylinder but is completely separate from the water which comes from the taps. Boiler may have an integral pump, which is why you cant see it, but it will have to be a pumped Primary system, gravity doesn't work backwards.

 

[fixitflav]

Hot water supply to taps may be on a gravity feed, i.e. there is a Cold Water Storage Cistern above the Cylinder somewhere, which feeds the cylinder which in turn feeds the Hot Water Taps.

The water circulating through the boiler and Radiators, will also probably be used to heat the Cylinder but is completely separate from the water which comes from the taps. Boiler may have an integral pump, which is why you cant see it, but it will have to be a pumped Primary system, gravity doesn't work backwards.

Not with you. If it really is C-plan (which I believe is fairly rare nowadays) it uses convection from the boiler to the HW cylinder. I don't see how that would work with the boiler higher than the cylinder.
OP - does it work? Do you get HW?

 

[MNW67]

.

 

[Madrab]

If the boiler has been moved to the attic and the HW cylinder is below it then it has to have been converted to fully pumped (Y or S plan), it couldn't work any other way.

 

[fixitflav]

If the boiler has been moved to the attic and the HW cylinder is below it then it has to have been converted to fully pumped (Y or S plan), it couldn't work any other way.

But does it work? OP hasn't confirmed. It wouldn't be unknown for somebody to buy a house and find problems with the CH/HW they hadn't been told about.

 

[Madrab]

But does it work? OP hasn't confirmed. It wouldn't be unknown for somebody to buy a house and find problems with the CH/HW they hadn't been told about.

Definitely wouldn't be no. I don't think that's what the question was though, there isn't any mention that the cylinder doesn't work? I think the OP is more just asking how could a C plan work (gravity circulation) with the boiler above the cylinder, short answer is it couldn't, so it can't be a C plan.

 

[ericmark]

My understanding is that the hot water works on a gravity feed, but with the boiler in the loft and the tank in the downstairs cupboard and no pump. How does the water circulate when the boiler is higher than the tank?

It doesn't C Plan is normally used with solid fuel, so with a power cut water still circulates, also used a lot with oil when there is no run on, again so no over heating when boiler turned off, the Y Plan is also used as default is DHW on so it can still thermal syphon to a small extent even when pump not running.

But boiler must be lower than the hot water tank, so it seems likely there is a pump built into the boiler so the coolant is forced around the system, and since it must be ensured the boiler never runs short of coolant it is likely it is now a sealed system.

 

[Hugh Jaleak]

Not with you. If it really is C-plan (which I believe is fairly rare nowadays) it uses convection from the boiler to the HW cylinder. I don't see how that would work with the boiler higher than the cylinder.

I think the OP may be getting confused between the Primary and Secondary systems. Hot water supply to the taps would still rely on gravity, (unless an unvented cylinder had been fitted). Primary side cannot work on gravity if boiler is higher than the cylinder, hence my suggestion there must be a pump somewhere.

Unless we're missing something and they've now got a Combi in the loft, but the redundant cylinder has been left in situ.

 

[fixitflav]

I think the OP may be getting confused between the Primary and Secondary systems. Hot water supply to the taps would still rely on gravity, (unless an unvented cylinder had been fitted). Primary side cannot work on gravity if boiler is higher than the cylinder, hence my suggestion there must be a pump somewhere.

Unless we're missing something and they've now got a Combi in the loft, but the redundant cylinder has been left in situ.

Until the OP comes back with some more information, we're never going to know

Edit - just noticed the question says system boiler. If that's the case, with in-built pump, it won't be gravity primary HW, or C-plan.

 

[Madrab]

C-Plan boiler system

I don't think they are actually saying it's a system boiler, more the boiler system is a C Plan, though could be wrong.

@Straiton70 are you able to respond and clear up a few things?