Please help me understand my problem and what I can do about it!!

[Phil12345]

Our boiler is currently on ground floor cylinder on first floor. We were planning to put the unvented cylinder in the loft as part of the work.

I wonder if the new 22mm pipe to te cylinder would do the job to improve the flow?

It blows my mind how much of this stuff seems like educated guess work but then again I can't get my head round pressure flow dynamic open etc!

So dan for clarity-

1 X 180l unvented with new 22mm copper to it?

Leave boiler as is until blows up and replace it then.

Add accumulator if flow and pressure isn't enough.

Would the 12l/min worry you for that configuration? (Assuming it was right) or would you have faith the 22mm copper would sort?

You're a legend by the way mate. People like me must frustrate the tits off you but you've been sound!

 

[bobdogavitch]

Time yourself filling a 2 Ltr bottle and work out the flow rate from the cold main that way. More accurate than a cup in my opinion.

 

[Phil12345]

Time yourself filling a 2 Ltr bottle and work out the flow rate from the cold main that way. More accurate than a cup in my opinion.

Kitchen tap provides 12l/min doing that bob

 

[muggles]

How about a powerful combi that can be range rated? I'd have thought the cheapest option.

"Cheapest" rarely means "Best"

 

[bobdogavitch]

Time yourself filling a 2 Ltr bottle and work out the flow rate from the cold main that way. More accurate than a cup in my opinion.

Kitchen tap provides 12l/min doing that bob

And you want 20?

 

[Phil12345]

As I understood it that's what I need to make an unvented worthwhile?

That's my ignorant bastard version of understanding of course Bob but I read it somewhere!!

 

[bobdogavitch]

How about a powerful combi that can be range rated? I'd have thought the cheapest option.

"Cheapest" rarely means "Best"

Totally agree. Just saying you could run a 34kw combi for your hot water and range rate the heating to maybe 15kw. Only offering an option. Cdi classics allegedly condense in hot water mode and can be range rated.

 

[Phil12345]

How about a powerful combi that can be range rated? I'd have thought the cheapest option.

"Cheapest" rarely means "Best"

Totally agree. Just saying you could run a 34kw combi for your hot water and range rate the heating to maybe 15kw. Only offering an option. Cdi classics allegedly condense in hot water mode and can be range rated.

See these are the options we have 34 kW boiler (although with only 12l at taps we were worried about poor flow for shower or unvented as discussed above

 

[Phil12345]

That's 12l/min open, with 1bar it went to 10.5 ish so we assumed 13 or 14l from the boiler was pointless as its not there to be heated!

 

[muggles]

How about a powerful combi that can be range rated? I'd have thought the cheapest option.

"Cheapest" rarely means "Best"

Cdi classics allegedly condense in hot water mode and can be range rated.

Maybe they do, maybe they don't, either way you'd be fitting a Wooshitter Botch which isn't generally advisable... most modern boilers can be range rated, but we're getting off topic now as a combi isn't the answer here

 

[bobdogavitch]

That's 12l/min open, with 1bar it went to 10.5 ish so we assumed 13 or 14l from the boiler was pointless as its not there to be heated!

Careful with manufacturers stated flow rates. Check what the temp rise is at the stated flow rate. It'll be lower at 40 degree C rise.

 

[muggles]

That's 12l/min open, with 1bar it went to 10.5 ish so we assumed 13 or 14l from the boiler was pointless as its not there to be heated!

Careful with manufacturers stated flow rates. Check what the temp rise is at the stated flow rate. It'll be lower at 40 degree C rise.

Makes no difference as this is OFF TOPIC - we've already established that he needs an unvented cylinder. Stop banging on about combis

 

[Phil12345]

Cheers muggles. So what to do about this 12l/min?

I guess the only way is to get the unvented, run the new 22mm copper to it and see what it spits out? Then look at accumulators and the like if I'm not happy??

Is there any other option for me really?

 

[bobdogavitch]

That's 12l/min open, with 1bar it went to 10.5 ish so we assumed 13 or 14l from the boiler was pointless as its not there to be heated!

Careful with manufacturers stated flow rates. Check what the temp rise is at the stated flow rate. It'll be lower at 40 degree C rise.

Makes no difference as this is OFF TOPIC - we've already established that he needs an unvented cylinder. Stop banging on about combis

Chill Winston. Just replying to Phil's comment above and Dan's about disparity between heating and hot water output.

 

[bobdogavitch]

Has anyone used those mains water pumps?