flow rate q

[novicegas]

Looking at changing my system boiler to a combi, combi will be positioned upstairs nearly in loft of first floor house. Q where do i test the water pressure and flow rate? Has been tested at back of the house on garden tap, however new position would be nearly as long but at least 5metres higher than that. Also anyone fitted one of those Salamander Home Boosts yet?

 

[gastec]

hello the out side tap is the best place to test water pressure and flow rate. your going to loose about 1bar on the mains in the loft. if you can rig it up get a test of the mains in the loft. you only get out what you put with a combi.

 

[Mike Jackson]

5 metres is 0.5 bar so you will lose slightly more than that taking into account pipework restrictions but flow rate is much more important. I won't entertain fitting a combi without at least 20 l/min for a 24Kw. I like to work on having twice the flow rate that the combi requires for hot water so that the flow through the combi won't reduce too much if someone operates a cold outlet.

The Salamander home boost looks a reasonable product but IMHO it's not going to be the cure all that a lot of people seem to be thinking. It will improve flow rates up to 12 l/min but this is still a fairly poor flow rate and will not be enough for a combi or unvented installation to work at full capacity.

 

[AWheating]

totally agree with mike.

 

[Centralheatking]

I dont like combis in roof spaces -
1. domestic hot water flow can suffer - esp. summer when all the hose pipes are runnin in unmetered gardens.
2. when the pressure drops its a pain to go up into roof void to re-pressurise
3. regs state that the area should be safe to access light/footboards etc.

Ur replacing a sound system with a more complicated combi AND a pressure pump to
make the combi work properly - I cannot see why

centralheatking