Will a new Combi boiler improve shower flow??

[Riley]

your understanding of unvented cylinders is wrong mate but all the same the OP should get one

 

[siricosm]

your understanding of unvented cylinders is weong mate but all the same the OP should get one

I am suggesting that if you have choice, it is better to have the boiler water in the tank, and the fresh in the coil, rather than the other way around.

 

[Riley]

What set up are you talking about????

 

[siricosm]

I have the 300l version of this:
Hygienic Buffer Storage Tank Vertical

 

[Riley]

I can’t see why a correctly installed and set up unvented cylinder poses a legionella risk

 

[Scott_D]

Thermal store?
Will use a lot more gas than a standard unvented cylinder unless you have another heat source that’s cheap/free

 

[siricosm]

It will if the temperature is too low. I run mine at 60C. Maybe in copper that would be OK.

 

[siricosm]

Thermal store?
Will use a lot more gas than a standard unvented cylinder unless you have another heat source that’s cheap/free

If you are going to keep 300l of hot water on standby I don't think it matters which side of the coil it is on.

 

[Riley]

I’m not convinced it’s anymore efficient

 

[Scott_D]

It will if the temperature is too low. I run mine at 60C. Maybe in copper that would be OK.

What temp at the tap at say 15lmp would a 60 heat store give?

 

[siricosm]

I’m not convinced it’s anymore efficient

It probably isn't more efficient, but it has some advantages. I listed them here a while ago. Sorry for the formatting, maybe I should repost it.

Experience with thermal store

 

[Riley]

So that’s the point it’s a thermal store not an unvented

 

[siricosm]

What temp at the tap at say 15lmp would a 60 heat store give?

Assuming the boiler can keep up with the heat load, it depends on the size of the coil. Ours is 4.5 square meters.

 

[siricosm]

So that’s the point it’s a thermal store not an unvented

I guess all hot water cylinders store thermal energy. The difference here is that the fresh water is in the coil, rather than the tank.

 

[Riley]

Yes but a big difference in terms of sizing and installing

 

[Riley]

And I still debate the legionella claim

 

[siricosm]

Yes but a big difference in terms of sizing and installing

We run a 300l system with a 22kw boiler. Same size as OP was quoted. We run ours at 60C, and it works fine.

 

[siricosm]

And I still debate the legionella claim

If you have a tank full of hot water at 60C there is some risk. Probably about the same as these daft cold water tanks in the attic, that necessitate separate hot and cold taps.

 

[siricosm]

We run a 300l system with a 22kw boiler. Same size as OP was quoted. We run ours at 60C, and it works fine.

Here is a pic:

 

[Jkb]

I have made my decision. See above. I’ll let you know how it pans out