Advice sought on Hot Water

60BOWENS

Our 5 Bedroom house has 38Cdi Combi Boiler installed last year as per a CORGI installer advice.It has got 3 ensuite and a family bathroom.Since our parents moved in we find our water pressure is too low in showers(and sometimes trikling) when any two ensuite is used or a shower and tap elsewhere is in use.
We would like to provide hot water supply to two ensuites from a seperate heating source.The present boiler provides right central heating in whole house.
What are our options and which would be cheapest in installing and in running cost?
If this helps-we still have a big tank in the loft.

Cardew

No combi provides enough hot water for two sources(like showers) to use at the same time. So even if you got another combi it still would not run showers in the two en-suites.

Presumably the tank in the loft is old cold water tank??

I am amazed that a Corgi* fitter recommended the use of a combi when you have 4 bathrooms(3 x en-suite and family bathroom) and didn't tell you of the limitations. IMO you could sue him.

A RGI** will advise if you can refit a hot water tank and use the Combi to supply hot water to that tank - it might be the cheapest option.

* Corgi have not run the gas registration scheme for about 3 years, it is now run by Gas Safe Register.

** RGI is now the term for a certified gas fitter.

twokcc

You really need an unvented hot water tank and a system(rather than a combi) boiler. Had similar experience to you nearly all the installers recommended a bigger combi -thats because they don't have the qualification to install a pressured hot water cylinders so you finish up with a system that is not fit for purpose. I've had a presurised hot water tank installed and it is possible to do it with a combi boiler. New to me property had a less than 18month old valliant combi installed and my plumber set up to run as a combi for new build but as a system boiler for hot water tank via use of zone valves/timers so have independent control of hot water/heating. Plenty of hot water without loss of pressure when other taps/showers turned on. If your pluber knew about you requirements you may have a claim for system not being fit for purpose may be an idea to get some advice.

60BOWENS

twokcc wrote: »

You really need an unvented hot water tank and a system(rather than a combi) boiler. Had similar experience to you nearly all the installers recommended a bigger combi -thats because they don't have the qualification to install a pressured hot water cylinders so you finish up with a system that is not fit for purpose. I've had a presurised hot water tank installed and it is possible to do it with a combi boiler. New to me property had a less than 18month old valliant combi installed and my plumber set up to run as a combi for new build but as a system boiler for hot water tank via use of zone valves/timers so have independent control of hot water/heating. Plenty of hot water without loss of pressure when other taps/showers turned on. If your pluber knew about you requirements you may have a claim for system not being fit for purpose may be an idea to get some advice.

Hi
Thanks for the advice.I do get some of what you wrote.Would you mind explaining it a bit more in detail?

macman

Even a powerful combi lacks the flow rate to supply more than one bathroom at a time. Pressure may also be an issue.
Did you specify a combi, or did the RGI simply choose the system for you?
Is your installer GSR? If done last year he certainly wasn't CORGI.

60BOWENS

macman wrote: »

Even a powerful combi lacks the flow rate to supply more than one bathroom at a time. Pressure may also be an issue.
Did you specify a combi, or did the RGI simply choose the system for you?
Is your installer GSR? If done last year he certainly wasn't CORGI.

We had a conventional boiler which had started playing up.So this installer advice 38CDi Combi.He is GSR registered and nor corgi.But at that time we were only three os us at home and used 2 bathrooms at max.
Now with more than 3 bathrooms being used,we find the water pressure a problem.Forgetting about how bad an advice we got and capabalities of that Installer-How can I deal with our problem now

macman

It's not the pressure, it's the flow rate. You can't do anything about it-the flow rate maximum is whatever it is. It should improve a little with the warmer weather. You either have to work out a 'shower schedule' or change back to a conventional boiler*.
A combi isn't suitable for such a property where bath/shower use is required simultaneously.
Have you had a discussion with your installer as to why he recommended this-having presumably carried out a proper site survey?

*or follow Cardew's advice and see if your combi can be adapted to feed a replacement hot tank. *But only after you find a new RGI*.

Cardew

60BOWENS wrote: »

How can I deal with our problem now

In principle there is no reason why a combi boiler cannot supply hot water to a tank.

It depends on what pipework/valves your RGI left in-situ when he(stupidly) converted your CH system to a combi.

You need to get quotes from two or three RGIs on the feasibility and cost of converting back to a conventional Hot Water system.