Combi Pressure

[Dmac]

Hi

This May Sound A Daft Question To You Guy"s Who Know About Plumbing Things, But My Question Is,

Does The Amount Pressure In A Combi Oil Fired, Sealed Central Heating System, Bear Any Relation To Poor Flow At The Hot Water Tap.

ie- Currently The Pressure Is Set At 0.7 bar If I Were To Increase The Pressure To Around 1.5 bar Would I See Any Improvement In The Flow Rate At My Hot Water Taps?.

Thank You

Mac

 

[30kw]

The water pressure of 0.7 baris not effected by it and increasing wouldnt do anything. the expansion tank is there to cater for expansion within the system as the boiler heats up. Check the flow rates with the manufacturers and test with a weir gauge, any less than stated could be due to mains water pressure, scale build up or too long and high resistance pipework. Some older combis have very poor floe rates, its in their nature!!!

 

[oilman]

30kWis right about the pressure, unless are doing a setup exercise on it, leave it alone. The higher you make the pressure the less the expansion can cope with the expansion.

In my experience, your low flow rate is likely to be a scaled up heat exchanger. They can be descaled in a couple of hours, alternatively a replacement could be £150.