New combi sizing - overspecced??!

[Dan Robinson]

I'm willing to believe you mate but you are literally the only person who has suggested that it would be worth it on 14l/min. I'm no fitter though! You want sales training I'm your man....!

It was 50/50 earlier?

You have 14 litres a minute through the 15mm pipe.

You want maximum performance from your shower. Even a 40kW Wooshitter Botch will only give what? 15 litres a minute at a decent temperature rise. Remember too, in the winter performance will be reduced further.

 

[Dan Robinson]

keeping my 16 year old boile

Which is?

 

[Phil12345]

Potterton ff50

 

[Dan Robinson]

Hmm, only heard of an ideal minimiser ff50

 

[Phil12345]

To be fair I'm not sure where I got the 50 from I miust have read it somewhere. It says on it ff from potterton

 

[Dan Robinson]

Pictures?

 

[Phil12345]

Just had the pcb replaced on it a few months ago but feels like I'm on borrowed time with it.

 

[Phil12345]

 

[Dan Robinson]

Looks like a tarted up Profile.

 

[Phil12345]

Don't know mate but have got paperwork from its install in 2000. I know some units can last donkeys years but in my head after 15 years you're on bonus time. Hence the worry about doing "the job" whatever that turns out to be and realising I've got a nice shiny cylinder and a knackered heat source. At least with a combo I've got a new heat source! As I say it's not the spending money, it's the wasting!

 

[bobdogavitch]

Couldn't you just get a smaller shower head?

 

[Phil12345]

I'm willing to believe you mate but you are literally the only person who has suggested that it would be worth it on 14l/min. I'm no fitter though! You want sales training I'm your man....!

It was 50/50 earlier?

You have 14 litres a minute through the 15mm pipe.

You want maximum performance from your shower. Even a 40kW Wooshitter Botch will only give what? 15 litres a minute at a decent temperature rise. Remember too, in the winter performance will be reduced further.

Sorry dan what I meant was 50 say unvented 50 say combi

But then when I ask about how flow rate now would perform with uv when with 22mm upgrade no one answers. And when I see videos (were they yours?) about an unvented if you don't then add an accumulater, the performance is absolutely terrible!

 

[Phil12345]

I'd love 30l/min and 4 bar - I'd have an unvented cylinder in already.

But I haven't got it and all opinion is it's a system that is unbeatable - if you've got the pressure and flow I don't have

Never debated the quality of the system but for a poor flow like mine it seems useless. You can have the keys to a Ferrari but if it's not got petrol you ain't going too far are you?

 

[Phil12345]

Couldn't you just get a smaller shower head?

Definitely mate but on my current gravity system I get 5l/min hot and I'd rather run around under my Britain electric than fine tune that mixer. It's freezing or red hot, no mix at all, as soon as you turn cold on at all it drowns it. So system needs changing for me.

Of course in amongst this if there is a clever way to get more/enough out the tap with what I have i'll put my money rifle down and enjoy my weekend £3000 richer than I thought I was!

 

[bobdogavitch]

There are pros and cons to every system. I play in a very busy band and I like to be able to have a shower if I want one if I get in at 3am. You can empty a smaller unvented cylinder pretty quickly. Whichever combi you go for (if you do indeed go for a combi) you'll need to up the gas. If you go for a larger output one chances are 22mm might not cut it depending on the length/complexity of the run but that's something your RGI needs to deal with. The difference in flow rate between a 30 and 34w boiler isn't massive, and, if showering rather than bathing you'll be using more gas and water over the same length of shower with a bigger boiler so bear that in mind. The prices of the larger combis gets crazy when you go for the bigger ones too, especially considering they're generally they're the same boiler with a bigger plate heat X.