Hot Water Query - Help Please!

[osprey]

We have recently had a new boiler fitted (combi condensing) and plumbed it to our hot water requirements in the house plus installed central heating (the house previously had none). However since then we have only been able to run one hot water tap at a time, no water comes out of any others at all. Is this normal and if not, what could we have done wrong?? Any advice gratefully received!

[migoplumber]

you need to supply a bit more information to clear any doubts.
Think you will find your pipe sizing is inadequate.

a combi can only heat so much water at a time, and if your opening 2 or more taps hoping for a supply of hot water, you will only get a dribble.

let us know what your trying to supply with your combi.

shaun

[Kings]

It's normal for combi type boilers to slow the water down, it does this as it heats it as you use it. This should reduce the tap pressure.
If there are any isolating valves on the cold feed to the boiler then make sure they are fully open, check you haven't got a pressure reducing valve on the mains in - you might need to tap off before this or increase the pressure.
You will also notice over time that hot pressure is lower this time of year as the temperature of the mains cold coming into the house will be colder. Things will improve come spring.

I would also get the installer back to check everything.

[dynamicddd]

Osprey, you may find the hot tap closest to the boiler gets the Lion's share of the hot water output. What you describe is typical of Combi boiler installations, but there may be things to try. Check the incoming cold main stopcock is open enough. Check the flow restrictor on the boiler (if applicable, some do have a restrictor that may have scope for adjustment). Kings' comment on water pressure being lower at this time of year isn't quite correct, it's the temperature of the incoming mains that is lower (as Kings stated - think they meant hot water temp will be lower at this time of year). Also, the kW output of the boiler plays a part in the temp (but not the flow rate) What output is the boiler?

[osprey]

Thanks for all the replies. The cold water inlet is fully open so its not that and its a 38kw boiler so pretty large. From the sound of it I think its just something we may have to get used to - just a bit of a shock after our old system! Will still get installer out to have a look just in case. Thanks again folks!

[Kings]

"You will also notice over time that hot pressure is lower this time of year as the temperature of the mains cold coming into the house will be colder."

Just to clarify - I meant that the hot water temperature will be delivered at a lower pressure/flow-rate due to the incoming cold mains being colder this time of year - therefore the boiler will slow it down so that it can heat it up. (in basic terms)
The actual pressure of cold mains will be the same but what you get out of the hot tap will seem slower over winter.

You may find that if one person is having a shower that all other persons in the house don't use the hot water, this may take a bit of getting used to - the good thing is you should never run out of hot water so loads of people can shower/bath as many times as they like.