Saunier Duval ISOMAX : does this increase hw flow ?

[Bhua]

Hello,

I have poor Hot Water flow through current combi (Therma23), probably I guess due low main pressure.

Would Isomax boiler increase the hot water flow ? Anybody tried this boiler ? Anything else I should do ?

Thanks

 

[chrishutt]

You need to determine whether the hot water flow is really sub standard or not - what is it in litres per minute? It should be around 9 l/min. Then what about the temperature rise? Should be about 35 C at that flow rate (check this on boiler manual).

If flow and temp. are to standard, you need to consider whether your mains supply is adequate for higher flow rates. If so, decide what sort of flow rate you require and look for a product that delivers. If flow and temp. are sub standard, you need to have an engineer check the boiler over.

 

[Bhua]

Thank you Chris. My current boiler flow is 11l/min for a 30 degrees delta, which seems to bad.
However, the main must be too low, and I was wondering if the hot water tank of the Isomax would increase the hw flow ?
Anything else to increase hw flow when main is low at 5th floor ?
Thanks

 

[chrishutt]

the main must be too low

Why do you think that? What data do you have to support that view?

 

[Bhua]

fair comment - I do not have any data except that flow is very low in the morning when most people use water in the building.
what I observe is a significant flow diference between cold and hot, which make the use of the shower very unpleaseant (too cold water or no flow)

 

[chrishutt]

If the problem is an inadequate flow of mains cold water, you will find that just as much a problem with any combi boiler.