gas boiler CH, immersion heater DHW = madness?

[dornfield]

Hi,

We've just moved to a large (five bed, two bathroom - 1 bath, 2 showers, five other rooms of various types) house and are surprised that in has a gas boiler (Worcester) to the numerous radiators but an (inadequate) immersion heater to the taps. Three people showering runs the system out of hot water on the top immerser, and the lower immerser is questionable as to its serviceability. We are tempted to change the immerser at least. Should we change the whole system to a larger Megaflow, or something else? Currently just the two of us, but if we're lucky, little ones would be nice. Maybe a brace of them. We have no intention of every trading up from this house. We expect to be here for 20 years, maybe 30 or 40, so long term solutions are welcome.

Oh, other developments: we intend to sacrifice one of the smaller bedrooms to be an indulgent en suite. No loo, just a big tub (BIG) and perhaps an additional shower. So possible two baths, three showers.

Thank you for any advice. We have British Gas visiting soon to advise. I'd like to sound knowledgeable!

Dornfield
[Any sufficiently advanced technology is indistinguishable from magic][/quote]

 

[petit_pablo]

Is the hw tank not heated by the boiler?

Immersions should only really be used as a back up on gas heated systems.

Do you know what the tanks volume is? Or just the measurements? (height x width?).

 

[dornfield]

The tank for the hot water is 166 litres. 120cm high, 45cm wide. It is completely separate from the gas boiler. The rational was that the gas boiler (situated in the integral garage) is physically too far from the taps in the house and the tank to supply the hot water. So the gas boiler does JUST the heating and the immerser does JUST the hot water to the taps. The two systems run independently of each other. It seems nuts to me!

Dornfield[/quote]

 

[bengasman]

In your situation, get a reputable installer to rip out the two cylinders and replace them with one largish unvented.
Judging by the mess you have found, it would be a good idea to get the whole system checked and all the problems sorted.
Best way long term is always to get it right as early as possible; patching up is just throwing good money after bad.

 

[dornfield]

My ignorance is legend....by 'unvented' you mean a megaflow system? I take it a megaflow requires a tank, and cannot be 'on demand'? Given the size of the tub we would like for the en suite, an on demand system would be attractive.

Dornfield

 

[bengasman]

The system is called “unvented” which works on main pressure, megaflo is brand name used like wellie or biro.
It does not require a tank and works on demand. Good return value and isolation compared to standard cylinder, which are horrible dirty unhealthy things.