Boiler replacement in a 4-bed detached

[mikej2005]

Hi folks,
I moved into a 4-bed detached house towards the end of last year which is heated by an old Glow-Worm floorstanding boiler that's probably as old as the house (~35 years old) judging by it's condition !

The boiler works fine but the problem is that it's costing a fortune to run - the bill for the three months over Christmas was about the same as I used to pay for a whole year in my previous 3-bed semi.

I've not yet decided whether to do a straight swap with a condensing boiler and keep the hot water cylinder or change to a combi/sealed system and get rid of the cylinder. I chose a Baxi Bahama for my previous house so haven't exactly had a good introduction to combi boilers ! (shudders)

With the current set-up, the hot water takes 2 minutes to reach the kitchen tap. I've not yet worked out what route that water is taking, but will hopefully sort that out when I re-do some of the pipework and radiators this summer.

In the meantime, I've got a few questions that I would appreciate some comments on :

1) Is a combi boiler suitable for a large-ish 4-bed house ? (kitchen, utility, 2 bathrooms and downstairs toilet)

2) The boiler is sited at the opposite corner of the house to the ensuite and main bathroom. Bearing in mind the delay I'm currently experiencing in getting hot water from the (much closer) cylinder, would changing to a combi potentially make this delay worse, not better, by doubling the distance and introducing an extra delay ?

3) What's the best way of working out how powerful the new boiler should be ? The current boiler has no other identifying marks on it, so I don't know the current rating.

Any comments appreciated.
Thanks.

 

[Agile]

Your gas bill is about what I would expect!

You seem to have missed that gas prices have virtually doubled over the last year?

You might get about 20% saving in GAS with a new condensing boiler but by the time the new one is fitted the price of gas will be up another 30%.

A combi will only supply ONE hot tap reliably! Just 9-15 litres per minute !!!

Tony

 

[Slugbabydotcom]

Hi folks,
I moved into a 4-bed detached house towards the end of last year which is heated by an old Glow-Worm floorstanding boiler that's probably as old as the house (~35 years old) judging by it's condition !

The boiler works fine but the problem is that it's costing a fortune to run - the bill for the three months over Christmas was about the same as I used to pay for a whole year in my previous 3-bed semi.

I've not yet decided whether to do a straight swap with a condensing boiler and keep the hot water cylinder or change to a combi/sealed system and get rid of the cylinder. I chose a Baxi Bahama for my previous house so haven't exactly had a good introduction to combi boilers ! (shudders)

With the current set-up, the hot water takes 2 minutes to reach the kitchen tap. I've not yet worked out what route that water is taking, but will hopefully sort that out when I re-do some of the pipework and radiators this summer.

In the meantime, I've got a few questions that I would appreciate some comments on :

1) Is a combi boiler suitable for a large-ish 4-bed house ? (kitchen, utility, 2 bathrooms and downstairs toilet)

2) The boiler is sited at the opposite corner of the house to the ensuite and main bathroom. Bearing in mind the delay I'm currently experiencing in getting hot water from the (much closer) cylinder, would changing to a combi potentially make this delay worse, not better, by doubling the distance and introducing an extra delay ?

3) What's the best way of working out how powerful the new boiler should be ? The current boiler has no other identifying marks on it, so I don't know the current rating.

Any comments appreciated.
Thanks.

No mention of how much the gas bill is there! Did you edit the post before Tony made his?

Your gas bill is about what I would expect!

Tony

Or is Tony psychic?

 

[Paul Barker]

Hi folks,

The boiler works fine but the problem is that it's costing a fortune to run

Oh no not another one.

I give up, somebody shoot me.

 

[mikej2005]

Your gas bill is about what I would expect!

You seem to have missed that gas prices have virtually doubled over the last year?

You might get about 20% saving in GAS with a new condensing boiler but by the time the new one is fitted the price of gas will be up another 30%.

A combi will only supply ONE hot tap reliably! Just 9-15 litres per minute !!!

Tony

Thanks Tony - yes, I do realise this.

Running cost is only one of the reasons why the boiler is going to be replaced. The others are :

1) size (huge)
2) location (taking up valuable floor space)
3) condition (thoroughly corroded everywhere - slow leaks over the years have rotted the floorboards and the flue, which emerges at waist height on the side of the house, is also corroded and lethally sharp)
4) pilot light - has to be on so fiercely that it must be adding to the running cost significantly. The pilot light alone keeps the large utility room warm

 

[mikej2005]

Oh no not another one.

I give up, somebody shoot me.

If you've not got anything constructive to say, then please don't bother. Hopefully your attitude isn't representative of this forum.

If the post doesn't interest you then move on - it's not hard, is it ?

 

[ChrisR]

Bloke in a London terrace complained to me that his winter quarter bill was £2800. I told him it was his fault for being a posh git but he didn't appreciate the information.

 

[gas4you]

if you really want to go down the combi route, which I would never recommend to a customer in a house this size, I think you would have to go for a storage combi such as the Vaillant Ecotec Plus 937, although this is very big on the wall.

I would recommend a heat only boiler and a mains un-vented cylinder assuming tyou have good cold mains pressure and the ability to run a 22mm cold mains supply to the cylinder.

Probably the most expensive option but I think the best.

 

[mikej2005]

if you really want to go down the combi route, which I would never recommend to a customer in a house this size, I think you would have to go for a storage combi such as the Vaillant Ecotec Plus 937, although this is very big on the wall.

I would recommend a heat only boiler and a mains un-vented cylinder assuming tyou have good cold mains pressure and the ability to run a 22mm cold mains supply to the cylinder.

Space isn't too much of an issue, as long as it's up on the wall and off the floor. I value reliability and performance more than a compact size.

I've not committed to the combi route yet but if I do, then a storage combi does seem like a good compromise.

I'm not up on hot water cylinders having never had one, so will need to read up on pressurised cylinders like you suggest if I decide a combi isn't for me.

Many thanks for the advice.

P.S. Some of the pipework (at the send and return for the heating circuit at the boiler at least) is larger than 22mm (27mm ?), presumably due to the age and overall capacity/size of the system - is there any reason why I can't replace this with the more modern, standard 22mm, presuming that any modern boiler is going to require 22mm ?

 

[Fluffster]

Pipework maybe 28mm as it is a large house for flow and return of the heating circuits.
You would have to work out your heat calcs for the whole house and boiler to decide if 22mm will suffice, generally in modern boilers it should do.
Ask in a few heating designers to get some more ideas as they will see your system layout and demand.

I would opt for a system boiler non vented heating circuit and a non vented cylinder
Pete

 

[Paul Barker]

Oh no not another one.

I give up, somebody shoot me.

If you've not got anything constructive to say, then please don't bother. Hopefully your attitude isn't representative of this forum.

If the post doesn't interest you then move on - it's not hard, is it ?

Snip
""Save space"... Tick.
"gas"... Tick (but not money due to installation cost capital cost and opportunity cost of what else you could have done with the money, you will do nothing but spend money, this is not a money saving excercise, don't be fooled by that great big scam)

More "reliable" than a pilot model gravity heavyweight?.... RAOFWL My Ideal Mexico ain't going nowhere, and I have a band A system boiler in the wings waiting to be fitted, but since the Mehico has not needed even so much as a thermocouple since 1997, what happened before that I can't tell you but it is still very young at probably 30 years old. A cost and management accountant (I got my foundation and was stufying for Part I's before I got bored to death sitting behind a desk entering CVP's and CVR's for Schlumberger group in London, josstling like wild animals to get on the train twice a day, but I do know how to make a capital decision) accounting would suggest that if the gas company will provide you a free pipeline to go with your new boiler you would better invest the money in the stock market and keep buying gas for the Mexico if he new the first thing about modern boilers age expectancy..

Your choice, but don't be woed by the need for big industry to make a profit for it's shareholders (become one of those shareholders instead with your money and make money also out of the millions of lemmings making these illadvised capital investments), and the need for our government to look good at world conferences...

I did a net present value calculation for someone else on hear, which probably largely went over his head as it was totally ignored, but it came out something like any saving on fuel would be swallowed up in repairs, you would come out about even on that but see no return on your investment.

Of course if parts are unobtainable for your old boiler then yes you have no choice. This is the means by which manufacturers are making sure you buy their new products."snip

Addendum, I have received new information, we (corgi registered folk) are no longer allowed to make good the casing seal on a heavyweight or the flue inspection cover seal with a generic Rottenbugger roap seal, we MUST use manufacturer's part (which of course is discontinued about 30 years before the boiler would have to be scrapped for any good reason). What that means to you good folk is that you are spared the choice of whether to have the heavyweight fixed or buy new boiler, and it doesn't matter two hoots whether you think I am barking mad (because I'm clearly out on a limb) or know something about capital projects.