no hot water and low pressure

[chefjuan]

hi. i was wondering if anyone can help me.
about a week ago the hot water in my house lost pressure and also started to take about 5 minutes of running before it became hot. i have an oil tank here and my boiler is a 'boulter combi 70, camray 5' when i checked the oil i noticed it was very low so i put the problems down to this. Yesterday however i had some more oil put in and still the problem persists. as soon as you turn the hot water tap on it comes out at normal pressure for about 5 seconds then reduces to almost a trickle.It then takes 5 mins of constant running/trickling to go warm(at best). The pressure in the cold water tap is ok and, i don't know if this is relevant but the central heating works fine also.looking in the boiler i've noticed the pressure gauge is at about 1 and a half but the gauge goes up to 5, i don't know if this has changed or always been at 1.5 because i've never had reason to check before now.
Anyones help in this matter is greatly appreciated.

 

[llykstw]

Well, the pressure gauge on the boiler is there to indicate the pressure in the closed central heating system. 1.5 bar is about right when cold - it may well rise to 2 or even 3 when the heating's on. The fact that the central heating works fine helps to work out what the problem might be - clearly the boiler's heating function is working fine, and there's no problem with the pump etc.

If there's not problem with the cold water pressure, then there's only one possible cause as far as I can see - somewhere, you have a blockage in the hot water system. If the same problem occurs at all hot water outlets, then chances are it's in the boiler itself, or in the outlet pipe. This blockage would impede proper flow, and unless the boiler detects a decent flow of water through the hot water pipes then it won't heat the water up, which explains why it takes ages to get warm or fails to heat up at all. Get a plumber in to determine where the blockage is and fix it.

Of course, I'm not a plumber, so this is really guesswork diagnosis on my part

 

[chefjuan]

thanks a lot for the help sounds about right.But being a complete newcomer to diy and such like, and also having read and heard plumber 'ooohhhh it'll cost ya' horror stories i was wondering if you or anyone else knew a rough price i would expect to pay.
thanks again for the help.