CH FAQ - boiler website

Not long ago I expressed some surprise to a plumbers' merchant at the number of non-condensing boilers on sale, which seemed to me to be disproportionate to the amount of installations where such a model would still be permitted, and he just shrugged his shoulders in that "I-couldn't-possibly-comment" sort of way...

David

|David WE Roberts wrote: |> Are a lot of the boilers on this site now no longer usable under the new |> regulations, or am I missing something? | |Not long ago I expressed some surprise to a plumbers' merchant at the |number of non-condensing boilers on sale, which seemed to me to be |disproportionate to the amount of installations where such a model would |still be permitted, and he just shrugged his shoulders in that |"I-couldn't-possibly-comment" sort of way...

I know of a non condensing boiler installed recently in a non domestic situation. As it only runs a few hour per week it makes perfect economic sense, as the extra cost of condensing would never be recouped.

Have a look at

Mogweed.

Since it's non-domestic the Part-L regs probably won't apply. However there is no doubt that the sales of non-condensing boilers are apparently far greater than they ought to be.

One thing to note about the Alpha CD50 that's not immediately obvious is that it's 600mm wide, as opposed to the usual 450mm....

Ben

Where would the manufacturers warranty issue be with non-condensing boilers. Are they bothered?

Presumably the products would still be covered under warranty.

sponix

It is far easier to get an exemption than people realise.

sponix

There is no restriction on the sale of non condensing boilers, only the installation.

Therefore there is no reason for the manufacturer not to honour the warranty.

Condensing and non-condensing boilers now are about the same price.

The thing about these stored water combi's is that control system is designed to bring in the boiler to put all its heat into the water store as water is being drawn-off ASAP. So, say a 60 litre unit will deliver far more than 60 litres of hot water. Those that have integral heat banks: Viessmann, W-Bosch, Gledhill, etc, may store water at 80C and blend it down, so more 'energy' is stored in the unit. Looking at say 60 litres and saying I have a 125 litre bath and it will not fill it, is not how they perform in real life. They also recover the full store from cold in a matter of minutes. Most are two flowrate levels. Full belt using the stored water and down to a lower instant rate when the store is exhausted. You 'never' run out of hot water.

Not so. Look at the form. You need a good case not to have a non-condesning boioer. With gas prices rising high than a kite people will 'want' condensing boilers.

So just 1200mm wide for a pair (plus a bit of gap), just the thing for unlimited lukewarm water on tap any time of day or night.

Lord Hall you are at it again today I see.

New regulations do not apply in Sctoland (yet, anyway)...

Speaking from my personal experience (A WB Highflow 440). It does drop down to a lower rate (I have to turn the hot tap down or I get cool water) after my large (1800x800) bath is around half full.

For the smaller bath 1600x700. It is nearly full before the rate drops.

I have deliberately not been too precise here as the above varies depending on the cold water temperature.

When the thermal store is empty (I assume) I have to turn the tap down in order to get hot water. I have never noticed an issue with showers or kitchen taps etc.

Mark

That is biggish. But the "overall" fill time must be reasonable though

So, a fast fill and it recovers in minutes.

The Alpha CD50 actually lowers the flowrate for you, to maintain hot water at a lower flowrate. I'm not sure if the newer HighFlow Greenstar does this too. Nevertheless your Highflow "never" runs out of hot water and will recover the store in minutes. I don't think you are dissatisfied with it.

It depends on what you mean by reasonable ;-) It's slower than my old vented cylinder system, but faster than other combi boilers I have experienced.

I omitted to mention that the recovery rate is indeed very quick.

The Highflow does not reduce the flowrate - the water just goes cool. As I said in my previous post I have to turn down the hot tap to get hot water at this point.

As regards to my satisfaction. It was the best I could afford. To that aim it is very good. However if I had more funds and space I would have chosen a different solution.

Mark

What would you have chosen and why?