Combi vs systems boiler for the 6th floor flat

[Mouse294]

Hi guys! We recently bought a place (top 6th floor flat) with systems boiler in place, cold and hot water tanks in the cupboard and a pump.
The pump and the boiler turned out to be broken so we asked our plumber whether we should switch to combi instead of replacing the systems one. He said that the water pressure was too low for the combi, that’s why we are stuck with tanks and systems boiler.
We called in another plumber for a second opinion and he was all for installing combi – he didn’t actually measure the mains water flow/pressure but checked the taps and said it would be more than enough and that he personally would not think twice about installing the combi.
I am inclined to trust the second guy more but I don’t know whether it’s because he is saying what I want to hear.
I would really appreciate any advice on this.

 

[Terry lambert]

The best thing to do would be to ask the installers back and get them to measure your dynamic pressure and flow.

Then post back they're findings

 

[Mouse294]

Couldn't get any plumber to come round this week so just measured the water flow rate with a bucket and it's around 16l/min in the kitchen.

 

[Agile]

That means very little!

You need the dynamic flow rate!

Tony

 

[shray]

Unless of course you live in a 8 bed 4 bathroom "flat" and require a worcester 42cdi with a flow rate of 17ltrs/min, then contrary to the previous post, fitting a combi should be totally fine.

Ps. Good luck flueing it at that height lol

 

[Mouse294]

Unless of course you live in a 8 bed 4 bathroom "flat" and require a worcester 42cdi with a flow rate of 17ltrs/min, then contrary to the previous post, fitting a combi should be totally fine.

Ps. Good luck flueing it at that height lol

Thanks for your reply, it's a 3-bed flat, 2 bathrooms but only 2 of us so hopefully will be alright.
P.s. - Actually, the flue is accessible via the balcony

 

[shray]

Balcony lol[/quote]

 

[Mouse294]

Totally confused now :-/ Had another plumber round today who said that he would keep the whole system and just replace the systems boiler.
He also said, combis are for 1 bathroom normally and we have ensuite and the main bathroom, 3 bedrooms, 8 radiators - apparently, systems would cope better with all this..

 

[Belboz]

FWIW.....

There are a few things you need to consider....

I had the same issue a few years back (albeit not a flat)

Assuming you have the option, then cost may be an issue but you also need to consider space (i.e. do you need the extra space), usage (albeit good combis now seem to have alleviated that issue) and, of course, how quickly you can get an engineer out in the winter when the combi breaks down and you have no backup...

Just my view FWIW.

 

[newbuildinstaller]

That means very little!

You need the dynamic flow rate!

Tony

As opposed to the static flow rate (at a guess that would be 0liters/min)