Combi-boiler or stored?

[IMM]

He doesn't use it all anyway, so will still have a great shower.

[Dave Plowman (News)]

Then your storage system was incompetently designed, or the shower not suitable. The flow rate from that is only limited by the head and size of pipes - not how quickly it can heat the water.

[Andy Hall]

Mmmm.

.andy

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[MBQ]

As soon as you resort to ad hominem attacks (as you always do), you have lost the argument.

MBQ

[IMM]

There was not an argument. Just me attempting educate the uneducated. I don't argue with him, I tell him.

[VisionSet]

Of course I should have mentioned that cost is a factor.

Those thermal stores look a great idea but they look pricey.

I suppose a combi is the cheapest option, but I have a feeling it won't be up to the job, simultaneous use, bath filling. I only have 3 bed semi - but for resale and our own use, perhaps combi isn't the way to go.

I guess if I go for anthing other than combi and consdidering I'm doing the whole system, except rads & pipework, I should not replace with old hat tank & cylinder. I suppose I can get a decent regular boiler for not much, is condensing worth it?

What are those German boiler manufacturers alluded to?

What sort of cost am I looking at for boiler, heat store, controllers?

[Christian McArdle]

For good quality components, you're talking between 1500-2000, including all controls, zone valves, condensing boiler, heat bank, programmer, programmable room stat. It could be done cheaper, if you intend to use less regarded brands, however the above will get you something decent, like a Worcester Bosch Greenstar and DPS heatbank.

Basically a stored energy mains pressure hot water system will cost you twice that of an equivalent quality instantaneous combi in parts, although the time spent fitting will have less of a difference and hot water performance will be in a different league.

Christian.

[Andy Hall]

If you are looking at short term sale then it doesn't matter because most buyers won't know the difference - especially if you sell in the spring to autumn when the water is warm.

Definitely. I have made savings of between 25 and 30% compared with my previous conventional boiler.

Worcester Bosch, Vaillant, Viessmann, MAN,......

For the lot, something in the £1500-2000 range if you want decent ones.

.andy

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[Dave Plowman (News)]

Of course many don't start from scratch and may already have a storage system much of which can be re-used.

[IMM]

The Alpha CB50 will do you fine. The flowrate is excellent and will fill a bath quicko and give excellent showers. Take no notice of amateur know-it-alls, a large flow combi is ideal for you. If I was you that is what I would go for.

It is also a very cost effective way to go, also saving valuable space in your semi.

[IMM]

Look at:

Worcester Bosch Greenstar 40kW condensing combi is good too.

[Andy Hall]

The marketing literature is full of claims which do not look nearly so good when the technical data is checked.

- The flow rate is specified as 18lpm but this is only until the 57 litre store is empty. This equates to a total of 90 litres mixed with cold water for a bath (which is not enough) After that it will be 11lpm because the output to water is 28kW.

- The marketing information claims that the vessel is fully recovered in 3.5 minutes. The data sheet says to 70% of capacity and with the boiler already running.

Quite.

Except that this isn't one.

.andy

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[IMM]

"When the store is fully charged an equivalent domestic hot water output of

50kW gives a flow rate of 18 litres per minute at 60°C, enough to fill an average bath in about 3.5 minutes.

If the store did run out 11 litres/min will still top the bath up. So, an average bath can be filled quicko. Showers will be high pressure.

That's if you have seen large flowrate combi. This man is wanting info to make a decision on a water system for his home. For his situation and needs the Alpha and Greenstar 40kW are ideal.

You acting the goat doesn't help at all.

[Dave Plowman (News)]

The standard answer from a fool regardless of the question or requirements.

Of course. You can only cope with simple installations. Hence the one answer to everything.

[VisionSet]

Maybe I'm overlooking something but it seems the prices are almost comparable

worcester bosch 40kw combi £1350

worcester bosch 28 HE system boiler & pandora heat bank £1500

I know you can get a cheaper combi - but to try and reduce performance problem...

This at present is leaning me towards the latter

-- Mike W

[Andy Hall]

This is bullshit marketing like music power on amplifiers.

It is not an equivalent power output of 50kW because it lasts for a short time.

Plugging the numbers in, the boiler will deliver 90 litres of water, mixed with cold at bath temperature. It will take longer than 3.5 minutes to do it as well.

After that, the remaining 60 litres of water needed for the bath will be at 11lpm.

They are completely different products.

The Greenstar could be considered to be "high" flow rate if you consider 16lpm at 40 degrees to be high flow rate. A storage system can outperform that in every way.

The Alpha has a tiny store and a standard sized burner and is very limited as a result. The marketing information that you have read is not borne out in the technical specs.

.andy

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[IMM]

An alpha CB50 is approx 1K. One box , on the wall. and performance is all you need.

[IMM]

< snip tripe >

[mike ring]

"Dave Plowman (News)" wrote in news: [e-mail]:

Not even by that, with a booster pump

mike

[Dave Plowman (News)]

Correction. All *you* may need. Not the same thing - by a long chalk.