combi min flow rate?

[topbanana]

i have a cold water mains flow rate of 12litres/min.
could someone please tell me whether this is suitable for a combi system,and whether i need to upgrade my combi boiler from say 24kwto 28 kw to increase performance.

 

[EliteHeat]

That sounds very low to me. I would have though 20 litres per minute would be the absolute minimum. A 30kW combi will be about 12.5 litres of how water per minute on the standard scale, a 24kW about 9.5, given your flow rate I can't see any point in upgrading.

Why not see if you can get the flow rate improved to your property?

 

[topbanana]

sorry, didnt explain myself properly.
I have taken out a conventional system and because of lack of space i was thinking of fitting a combi24kw.
So not yet fitted.
Also i was thinking of installing it in the loft to further increase my limited space. would this further reduce my flow or pressure.?

 

[ChrisR]

Is that with all cold taps open, combined?
If so forget a combi until/unless you can improve it.

 

[Gasguru]

Just quoteing a flowrate is insufficient to determine whether a combi is a feasible option.

You need to connect a pressure gauge to the incoming main, then turn on the kitchen sink tap. You can then plot dynamic pressure with differing flowrates. Untill you have done this don't proceed any further.

The legal minimum the water companies should supply is about 1 Bar at 9 litres/min at the stopcock at ground level ie just enough for a shower. I think they only consider compensation when it drops to 0.8 Bar (not uncommon)

 

[topbanana]

only one tap available in property next to mains on ground floor.