Combi/Y plan hybrid conversion

[dannyd]

Hi all,

I've just moved in to a new house which has a combi fitted but appears to have some very strange plumbing in place. The DHW output is connected to the kitchen tap only. The remaining hot taps are connected to a cylinder.

CH output from the boiler is connected to a mid position valve which feeds the CH circuit (single zone) and the cylinder and this side of the circuit appears to be wired as a Y plan.

I'd like to convert this to combi as its a bit wasteful to heat the full tank of water as it very rarely gets used. I think the reason its been done like this is because the boiler is in the kitchen at one end of the house and the cylinder is in a bedroom at the other end.

Is is possible to reuse the existing flow to the cylinder currently on the CH circuit for DHW? I was thinking of connecting this to the DHW output on the boiler and then at the cylinder end connecting the flow to the hot water outlets, bypassing the cylinder.

Would this work or would it take a long time for hot water to reach the other taps?

Thanks for your help
Danny

 

[Dotty]

Leave it as it is. You'll find your hot water system has been designed for the needs of the house which the combi would struggle to deliver.

The dhw output of a combi is often misrepresented and/or misunderstood.

 

[snowhead]

As above, leave it as it is.
It's just as wasteful firing up a combi to heat a cup full of hot water to wash hands in a bathroom.

What's worrying tho' is this statement;

its a bit wasteful to heat the full tank of water as it very rarely gets used.

Does nobody regularly wash/ bathe/ shower in your house?

Just set the timer for the hot water to Once a month for a tank full.

P.S I hate combi's.

 

[erj]

leave it alone, combi,s are not the answer to every thing. Give me a cylinder any day

 

[newcastle phill]

All of the above.

 

[Masood]

Excellent advice above from my colleagues. I would add that you've got two very useful advantages in the system you've got.

If the mains water is shut off for any reason, you'll still have a tankful of water available. Second, if your boiler packs up you can have hot water from the immersion heater as a backup.

It's a robust system design, leave it as is.

 

[AWheating]

if anything consider upgrading the cylinder to an unvented one to give you better hot water and probably better heat retention.

 

[Ermintrude]

Might have shister mains hence o/v

 

[lame plumber]

smaller water bill as your not wasting cold water prior to hot coming through, very green