Combi boiler to heat up unvented indirect cylinder to improve shower flow.

[60BOWENS]

Hi
Our 38CDi combi cannot cope with supplying hot water to 4 bathrooms in our house.In fact when somebody uses a tap downstairs the shower flow stops!!
We have been told we can use our present combi(which is less than 3 years old) to heat up radiators AND/OR unvented cylinder using motorised valves.
We use showers in morning and central heating in night(that too during winter)
Will appreciate any help/tips/guidance on this.
Which brand makes 300L cylinder which is affordable and dependable.
Apart from motorised valves is there anything else I need to insist upon?
Many thanks

 

[Dan Robinson]

Apart from motorised valves is there anything else I need to insist upon?

That will be self evident to whoever carries out the work.

 

[picasso]

And someone to check the pressure /flow of your incoming mains supply or you could be very disappointed.

 

[60BOWENS]

Apart from motorised valves is there anything else I need to insist upon?

That will be self evident to whoever carries out the work.

Seven Plumber/gas engineers came and gave seven opinions!!

 

[60BOWENS]

And someone to check the pressure /flow of your incoming mains supply or you could be very disappointed.

Yes
Had it measured
22mm mains
very good pressure and flow is measured

 

[Aquaheat]

And someone to check the pressure /flow of your incoming mains supply or you could be very disappointed.

Yes
Had it measured
22mm mains
very good pressure and flow is measured

You really need to provide a bit/lot more information to get any form of informed response.

What was the flow rate? Pressure? What is the house construction? 2 floor 3 floor etc? What are you trying to run? Your 7 guys what were their 7 opinions?

Help us to help you. The more you can tell us the better chance of a sensible response.

Look at it this way, you have had 7 guys come round who had the benefit of being able to see the site, carry out tests and have an in depth discussion with you about what you want to achieve yet you ask on an Internet forum and give scant information and hope to get a definitive answer.

Please don't take this as a dig, yes we are good but we haven't yet done the mind reading course

Jon

 

[Dan Robinson]

we haven't yet done

My jedi skills are pretty good, trust me mind reading is very overrated.

 

[jedi]

Apart from motorised valves is there anything else I need to insist upon?

That will be self evident to whoever carries out the work.

Seven Plumber/gas engineers came and gave seven opinions!!

I feel your pain..

 

[60BOWENS]

Our mains is 22mm pipe with flow of over 30L per min and good pressure (of 5bar or so).
Reason we are confused and seeking some advice was because one of the expert said it is impossible to use present combi (38CDi) to heat up unvented cylinder and asked me to go for Direct unvented cylinder.
Another person came and said we should dump the combi and get old system with vented cylinder installed.
Third person said keeping Combi for radiators and kitchen taps but solar heated water supply for upstairs.
Two tradesmen talked about using combi to heat up the unvented cylinder AND radiators.One of them said he couldby the way of using 2 motorised valves achieve this and said 300L cylinder would be adequate for our 4 bathrooms.But other person said 210L is what we need but his "ballpark figure" was £500 more than other person.

main reason we are asking for help/guidance/tips is we were once conned by a "gas register safe expert" who advocated and installed a combi boiler for a detached 4 bedroom 4 bathroom house!!

 

[muggles]

Our mains is 22mm pipe with flow of over 30L per min and good pressure (of 5bar or so)..
Two tradesmen talked about using combi to heat up the unvented cylinder AND radiators.One of them said he could by the way of using 2 motorised valves achieve this and said 300L cylinder would be adequate for our 4 bathrooms.But other person said 210L is what we need but his "ballpark figure" was £500 more than other person!

These people are correct. I'd go with a firm estimate rather than a ballpark figure, and make sure they're installing a decent quality cylinder. The boiler will end up being oversized for the system but you have what you have so you'll have to make do with it. Having said that, you could make use of the boiler's power and install an ACV Smart 210, which is a 210L cylinder that has a much faster heatup time than other cylinders, meaning that it can be a smaller stored capacity

As for being wary of tradesmen, use someone who comes recommended by a neighbour, or of it's running in your area then www.buywithconfidence.gov.uk is a Trading Standards run trusted trader scheme, where you'll find lots of quality tradesmen

 

[stardanny]

With 4 bedrooms and 4 bathroom, you'll be better off with loft cold storage tank and vented cylinder.

4 bathroom Ffs!

Daniel.

 

[Agile]

main reason we are asking for help/guidance/tips is we were once conned by a "gas register safe expert" who advocated and installed a combi boiler for a detached 4 bedroom 4 bathroom house!!

That is clearly seriously wrong.

But I see you as also conning SEVEN installers by getting them to visit you solely to give you free advice!

Only one of them could ever do the job!

Tony

 

[Agile]

Our mains is 22mm pipe with flow of over 30L per min and good pressure (of 5bar or so).

But those do not exist at the same time!

You need to measure the dynamic flow rate being the flow rate whilst leaving say 1.0 bar in the supply pipe.

How many people live there?

Tony

 

[Aquaheat]

we haven't yet done

My jedi skills are pretty good, trust me mind reading is very overrated.

I knew you were going to say that.

Jon