Poor Hot Water Pressure Combi Boiler

Hi all,

Only my second post for help, but everyone seems so helpful so I thought I'd try again. If anyone needs some Building Surveying advice let me know

I have a Worcester Bosch 24i combi boiler (not Junior or Greenstar - the older one) and the hot water pressure is rather poor.

It's reasonable for having a shower or filling the sink but running a bath takes ages and if you use more than one hot water tap at once the one furthest down the chain (I assume) just runs at a pathetic trickle. No chance of a shower when the washing machine's on.

Is this normal?

If not, does anyone have any ideas?

Although I've not measured it, the cold water pressure here is amazing so I'd be surprised if it was a result of that. I had to have a new water main fitted from the meter into my house and the engineer who fitted that commented on how high the pressure was.

Not sure how much info you need, but here's some more for good measure!! The boiler is used for heating and hot water, and is located in an upstairs bedroom. The bathroom is also upstairs. I live in a small 3 bed end of terrace and it's just the two of us here (and our cat!).

Thanks in advance of all your kind help.

Mark Newman

hi mark,
assuming your cold pressure is ok going into the boiler the i would check the valve on the cold inlet to ensure it is fully open or somewhere near.
if it is then you need to be looking at the flow restrictor and ensure its not blocked or partialy blocked.
dont know how old the boiler is but theres a chance that the heat exchanger could be scaled also.
these are the common problems and if they are ok then we will look at other things.
hope this helps

neal

It sounds alright to me, it's only a small combi, and only gives 11 ltrs a min of hot water at a 30 degree rise. You can check it with a bucket and thermometer easily enough. Just measure the temp of the cold, then time how long it takes to fill a, say ten litre bucket. Adjust the hot tap flow to give about 11 lits a min and see if the water temp is 30 degrees or so more than the cold. If so then it's doing it's job. If you want to radically improve your hot water, and you can with good mains supply, you will have to get the biggest combi you can.