No gas and a combi = no showers

[^woody^]

The point was that if they had NOT succumbed to the salesmen pushing combi boilers and retained their hot water cylinder with its immersion heater then they would have still had hot water. They were not whinging about loss of gas supply. They were not happy that the dis-advantages of a combi had not been fully explained to them.

The cost savings of a Combi, some controls and a lesson in change of habits far outweigh the cons of the scenario you have posted about.

Particularly for the less well off, social and supported housing tenants and those in fuel poverty. I could point you in the direction of thousands of people who have been able to enjoy (ie afford) warm winters for the first time in many years after having their system heater and cyclinder swapped for a Combi.

 

[^woody^]

If your going to have a combi have an electric shower

If you want cold showers every time a tap or toilet is used.

 

[Nozzle]

and you'd been stockpiling diesel too ......

http://www.bbc.co.uk/news/uk-43923056

Who knew!!! (That the dye can be taken out of red diesel)

Nozzle

 

[bernardgreen]

The cost savings of a Combi,

Cost savings ? when the efficiency of a combi can be as low as 30% when used to supply hot water is several small quantities spaced a few minutes apart. (( Building Research Establishment results )

 

[^woody^]

Cost savings ? when the efficiency of a combi can be as low as 30% when used to supply hot water is several small quantities spaced a few minutes apart. (( Building Research Establishment results )

Yes cost savings. (Real life results)

 

[Nozzle]

No heating up hot water and not using it.

Not what I've heard... you have to run enough to flush the cold with hot plus of course the water that replaces the same for combi or system. But with the combi, you also have to heat the mass of the heat exchanger again - every time.

Combi... heat "only the water you need". <plus the cold leg in the pipe, plus a chunk of Stainless/ali>

Nozzle

 

[^woody^]

Not what I've heard... you have to run enough to flush the cold with hot plus of course the water that replaces the same for combi or system. But with the combi, you also have to heat the mass of the heat exchanger again - every time.

Combi... heat "only the water you need". <plus the cold leg in the pipe, plus a chunk of Stainless/ali>

Nozzle

Tip: install the Combi in the same house, not at the end of the street.

 

[Nozzle]

Combi installed in compact flat where there's no space for a system = short pipes
Combi installed in a 4 bed house = long pipes. Simples!

Each metre of 15mm copper = ~130ml
Each metre of 22mm copper = ~310ml

Nozzle

 

[Bodd]

If you want cold showers every time a tap or toilet is used.

Now that would depend on bar pressure L/per min Kw’s and brand of Boiler.

So not always

 

[Bodd]

Not what I've heard... you have to run enough to flush the cold with hot plus of course the water that replaces the same for combi or system. But with the combi, you also have to heat the mass of the heat exchanger again - every time.

Combi... heat "only the water you need". <plus the cold leg in the pipe, plus a chunk of Stainless/ali>

Nozzle

There’s plenty s reason why not to have a Combi. But best weigh it up flat by flat house by house.

What you said there it’s cold water your wasting until the hot comes.

I fitted a Combi in France that had a secondary return. And a small storage cylinder within.

 

[Bodd]

Tip: install the Combi in the same house, not at the end of the street.

I’m amazed when I go to these new built flats in London where the designer has put the Boiler the opposite end to the Kitchen and Bathrooms

 

[Bodd]

Combi installed in compact flat where there's no space for a system = short pipes
Combi installed in a 4 bed house = long pipes. Simples!

Each metre of 15mm copper = ~130ml
Each metre of 22mm copper = ~310ml

Nozzle

The problem is not the Combi it’s who fits a Combi. There’s so called plumbers who know only how to fit a Combi.

 

[gasbanni]

The point was that if they had NOT succumbed to the salesmen pushing combi boilers and retained their hot water cylinder with its immersion heater then they would have still had hot water. They were not whinging about loss of gas supply. They were not happy that the dis-advantages of a combi had not been fully explained to them.

Apart from hot water, they don't have any heating either ....,but there again if they'd kept their coal fires and back boilers they'd have heating and hot water wouldn't they ?

It's a rather silly post, it's not often the gas supply fails but when it does it ain't just no hot water. There again with a combi they never run out of hot water and have to wait for a cylinder to heat up. Pros and cons.

 

[bernardgreen]

Apart from hot water, they don't have any heating either

In many cases when it is clear the interruption wil be prolonged people are given electric heaters and / or a single electric hob by the gas supplier. A friend still has the hob she was given. When she tried to return it the gas people told her she could keep it. ( maybe for the next loss of supply incident ? )

Pros and cons.

Obviously but the pros get highlighted and the cons are not always spoken about. And it can be the boiler has failed and not the gas supply.

 

[Nozzle]

What you said there it’s cold water your wasting until the hot comes. .

That's only true the first time - every draw after that, the cold water that is coming out is water that was once hot and whose heat has been wasted. ~550 J/C per metre (of 15mm) infact (and that's not including the mass of the copper).

So as not to loose the gist of my point though - this heat is lost whether its system or combi, makes no difference. What is does do though, is blow the concept out the water that "you only heat what you use" thereby negating one of the aledged USPs of the combi set-up. And the smaller quantity someone draws from the DHW of a combi, the worse the problem gets - as the heat exchanger needs heating every time no matter how much is drawn.

Nozzle