New build heating query

[LMC]

Hi all, I'm in the process of buying a new build home. We went round a few developments and as far as I can see the heating systems are similar, but I can't figure out what they are...

The house I am buying has both gas and electric. The heating system consists of a combi boiler in the kitchen and a tall but narrow water tank in a cupboard.

In my own house, I got a combi boiler fitted last year. Mine is absolutely huge while this new one is really small. My boiler does everything, the bath/shower, the radiators, all hot taps.

Are the new build system some sort of dual purpose set-up ie a combi boiler with an electric immersion type back up, or does one part do things and the other different things ?

I'm confused. The only folk available to ask were the sales agents who hadn't a clue. I'd hate to have to go back to the old days of heating a whole tank of water just to have a shower.

Thanks

Les

[Plotloss]

Sounds like a megaflo

Not sure though, plumbing confounds me, everything is the same colour, how do you work out which pipe does what?

[mk1fan]

Don't be put off by size!! Boilers in new properties don't need to do a lot of work as the buildings and systems are well insulated. The tank will be massive but it will have 100mm+ of insulation around it under it's shiny white exterior.

What ever system has been installed it should be efficient and require little energy to run.

[Deva Link]

If it had a Megaflo type of system I would have thought that would be mentioned as a feature as they're pretty expensive.

Combi's aren't best suited to large family homes with multiple bathrooms.

[LMC]

The new house has a downstairs w/c, main bathroom on 1st floor and ensuite with shower on 2nd floor. If I remember right, the tank is on the 1st floor, the boiler is in the kitchen on the ground floor.

[fido]

are you sure it's a combi- and not a regular type of boiler?

[LMC]

fido said:

are you sure it's a combi- and not a regular type of boiler?

No, not sure at all. I just thought it looked like a small combi.

[Deva Link]

LMC said:

fido said:

are you sure it's a combi- and not a regular type of boiler?

No, not sure at all. I just thought it looked like a small combi.

I don't think there's any such thing - I was assuming it was small "system" boiler.

[andy43]

Tank could be a thermal store - google gledhill boilermate. Note (I think) Gledhill may have gone bump.
If tank's much smaller than you would expect, chances are it's a thermal store.
Cheaper for the developer as they're less well-regulated than unvented cylinders.
Are you sure the boiler is definitely a combi and isn't a condensing boiler misdescribed by the sales people?
Condensing just means it's 90+% efficient, a condenser could be any type of boiler combi or otherwise.

[Gingerbread Man]

Not a combi if it heats a cylinder.

[B17NNS]

Plotloss said:

plumbing confounds me, everything is the same colour, how do you work out which pipe does what?

Scratch through the copper coloured insulation with a hack saw.

Gas pipes smell a bit, cold water buuurrrr shiver, hot water burny burn ouch, flow and return radiator pipes contain dirty water, one will be a bit hotter than the other.

Simple when you know how!

[miniman]

Did the tank have one or more smaller, calor-gas-bottle sized appendages? If so it is a megaflo or similar. In other words, it is pressurised.

[LMC]

miniman said:

Did the tank have one or more smaller, calor-gas-bottle sized appendages? If so it is a megaflo or similar. In other words, it is pressurised.

I really dunno, because it was just a quick look and on to the next room. One thing I'm [pretty] sure of, is that there is no header tank. Our bedroom takes up the entire roof space.

[Paul Drawmer]

miniman said:

Did the tank have one or more smaller, calor-gas-bottle sized appendages? If so it is a megaflo or similar. In other words, it is pressurised.

I've got this arrangement, but it isn't a heat store.

My DHW is not pressurised.

[Defcon5]

^ What do the pressure dials on the pressirised cylinders refer to then?

[John MacK]

^ There are 2 expansion tanks/cylinders/vessels in the picture.

What's a pressurized cylinder?

[miniman]

John MacK said:

^ There are 2 expansion tanks/cylinders/vessels in the picture.

What's a pressurized cylinder?

Well, it's a cylinder that is pressurised

i.e. it means that it will provide high-pressure hot water without the need for a pump. We have a 3-storey house and the cylinder is on the top floor. If it was a conventional cylider, we'd get bugger all hot water in the bathroom, which is also on the top floor.

[John MacK]

miniman said:

John MacK said:

^ There are 2 expansion tanks/cylinders/vessels in the picture.

What's a pressurized cylinder?

Well, it's a cylinder that is pressurised

i.e. it means that it will provide high-pressure hot water without the need for a pump. We have a 3-storey house and the cylinder is on the top floor. If it was a conventional cylider, we'd get bugger all hot water in the bathroom, which is also on the top floor.

Which one in the above picture is the pressurised cylinder?
They both look like expansion tanks to me.

Where does the pressurised cylinder in your house get its pressure from?

[Dave_ST220]

Do these pressure systems only apply pressure when the water is "on" or do they store the water in the tank so always pressured? I'm going from a combi(st-nice burns if someone flushes bog downstairs) to one of these systems. Good thing about combi is hot water on demand-how do these new systems work? Thermostat so if water drops to below temp it will kick in? Thanks.

[miniman]

John MacK said:

Which one in the above picture is the pressurised cylinder?
They both look like expansion tanks to me.

Where does the pressurised cylinder in your house get its pressure from?

Neither is the pressurised cylinder. I haven't got a clue how it gets its pressure, all I know is that from time to time I have to open a valve on what you describe as an expansion tank until the pressure indicator rises above 1 bar.

Dave_ST220 said:

Good thing about combi is hot water on demand-how do these new systems work? Thermostat so if water drops to below temp it will kick in? Thanks.

Ours works twofold:

1. We have a solar panel on the roof which has a dedicated control box. If the temperature in the roof panel is more than 5 degrees higher than the water in the tank, the pump comes on and circulates the hot water to heat the water in the tank.

2. On a normal timer system, the water is heated when the timer calls for it. When the system is on, the boiler will kick in when the thermostat on the hot water cylinder (which is separate to the stat for the solar system) switches it on.

HTH