Low water pressure Hot and Cold

[nickwhittaker]

My water presure seems low - the mains is fine. My Cold water to the bathroom is taken from the main header tank in the loft via 22mm pipe. The Hotwater is likewise supplied from hot water cyclinder and that is supplied from the same header tank again via 22mm. The pipework has been flushed so sure there are no blockages, the taps and service valves are all fully open and the tank is a good 8 feet above the bath etc. Any ideas why this could be ?

thanks

 

[dan21mag]

airlocking!!!!! probably... how did u flush the pipework????

 

[nickwhittaker]

I drained the entire system. Rads from a drain valve at lowest point. Hot water from a drain valve near bottom of the HW tank. Have blead all Rads and CH works fine. HW is hot but low pressure. How do you bleed HW systems ?

thanks

 

[dan21mag]

airlocking most prob... the 22mm feeds from loft cistern may not b at a suficient gradient to expell the air when refilled...
answer: back feed the pipework with mains pressure to elimante air..
maybe via mixer in kitchen, open up hot and cold, hold rag over tightly and blast through fot 30 secs... hope this helps....

 

[nickwhittaker]

Cheers mate - so I run a hose from the kitchen tap (mains pressure) to taps in bathrom and force mains water back up the hot and cold to clear the airlock - is that right ?

thanks

 

[dan21mag]

yes.. should do the the trick.. let me know how u get on