Worcester Bosch 30 CDi Pressure Problems

[lowton74]

Hi everyone.
I have a 4 bedroomed detached property and I have just had a Worcester Bosch Combi Boiler fitted as it was cheaper than replacing my leaking hot water tank.
Now complete, I have a pressure problem.
I have always had good hot and cold water pressure in the house, so much so that the mixer shower was like a jet wash, but since the combi has been fitted the pressure is a lot less in both cold water and hot water.
When I run the mixer shower in the en-suite I cannot have any other tap running in the house. If any other tap is opened in the house the shower just stops.
I called the plumber and he said that this is normal for a worcester bosch and it's something we have to live with.
I cannot believe that this is normal for such an expensive and popular system. I also have safety fears if the shower stops whilst someone is in there and then restarts suddenly with the water at a higher temperature.
Is there anything that I can do to increase the pressure in the system? Is there anything that the plumber could have overlooked and is he just using a Kop out explaination for the combi system?

Help required.
Thanks

 

[justlead1]

Hi. They work in direct relationship with mains pressure and volume. It is normal practice for a plumber to assess this before suggesting for installation. Your first port of call being the stopcocks on the main water supply. Making sure they are fully open and no other restrictions are present in this pipe.

 

[tackleburger]

I think you've been had my friend. I can't imagine a new combi/system change over ever being cheaper than a cylinder swap and it sound like you may have had a decent set up before such as an unvented if you had better pressure before or just a well designed low pressure system. Either way this is a disgrace by the sound of it.

If you provide more detail such as what you had before, where it was located price quoted etc I think you'll get more responses. I just can't see how the cylinder change would ever be more than a boiler in these circumstances.

Incidentally the 30 CDI will only provide 12 litres per minute at a 35deg temp rise so in the winter this will get slightly worse.

 

[newbie1]

as above cylinder swap tops 400.00
30cdi and fitting must be 2000.00
what was the plumbers name john wayne
imho this cowboy should be round your house looking into this problem as first thing to check when fitting combi is flow rate of incoming main

 

[grahamgas]

Another cowboy, opting to advise to replace the boiler than to change the cylinder.

I have seen this countless times where, because the installer only knows where and what the pipes do on a combi that is all they stick in.

Lets hope we dont have another really cold winter, otherwise you will be able to wee quicker, than what the boiler can produce.

Did the guy take any pressure/flow measurements?

With a 4 bed house I am guessing that you might have more than 1 shower/bath.

As already said, a cylinder change would not of been dearer than a boiler install, unlkess of course the boiler was stolen!

Graham

 

[Plucky]

This in an outrage.

 

[aggis]

If you find the stop tap turned down & you open it fully & it improves the flow rate at all taps, you may need a pressure reducing valve fitted near to the stop tap, as excessive water pressure could give poor hot water performance with a combi. Ideally the PRV should be set at @ 2.5 bar [3bar max]
If this is the case, he should have fit one!!!!
Get him back.

 

[Centralheatking]

I hope it is a technical prob with the boiler or mains water supply, there is
enough advice above about checking that.

The real person doing the checking and sorting your problem out is the installer who should have a gas registartion no. either the old corgi or new gas safe one depending on when it was installed.

GET HIM BACK give him a chance and then contact trading standards he might not have supplied a boiler 'fit for purpose'.

There is a way around it we sorted one out a few years ago that
someone else screwed up but its not a cheap solution

centralheatking

I have just noticed your address - we cover West Lancs so we would look f.o.c. if he wont fix it

centralheatking

 

[tackleburger]

You could get a cylinder installed off the combi if that's possible.

It is so annoying. This kind of thing put's customers on the backfoot with you as there is always the suspicion thanks to guys like this. The other thing is there are a good honest jobbing plumbers out there who are struggling and would have loved to swap a cylinder.