Best valiant boiler for 300 Litre tank (6 bed 3 bathroom including loft)

[mrbg07546]

I have a very large semi detached - 6 bed and 3 bath about 15 rads.

reason for the valiant is boiler guy is advanced valiant hece the 7 year warantee.

I want to get a 300 L tank(unvented cylindeR).

1) what boiler size? 37kw boiler man reccomended but i believe its over skill. I think 30 kw max.
2) theres a new Green IQ valiant boiler - is this worth it? its only 27kw. will it be as easy as normal boilers to install.
3) what tank brand? boiler man reccomends tempest.

 

[stardanny]

3 bathrooms?

What the working pressure and what the flow litre per minute? Water system is depend on this.

Daniel.

 

[mrbg07546]

Just replaced a new lead pipe (which was 2.8bar at 15lpm). Now I have 2.8 bar @ 40+ lpm

 

[mrbg07546]

Cloak:1 toilet basin
Ensuite:shower basin toilet
Main bathroom:shower,bath basin toilet.
Loft bathroom: bathroom basin toilet

 

[Agile]

Just replaced a new lead pipe (which was 2.8bar at 15lpm). Now I have 2.8 bar @ 40+ lpm

I don't believe you!

You have a STATIC pressure of 2.8 bar.

And an open pipe flow rate of 40 li/m.

Hopefully you might get about 25 li/m @ 1.0 bar dynamic flow rate which is just adequate for an unvented!

What is length and size of plastic pipe have you fitted?

The boiler rating depends on the heat loss of the property! Have you calculated that?

Tony

 

[The831Bunny]

Please don't say he needs to add 3Kw for the cylinder Tony...

 

[DP]

Please don't say he needs to add 3Kw for the cylinder Tony...

Bet the man is thinking about it

 

[mrbg07546]

Ok I used to get 15lpm at 2.8bar with the lead pipe. I now get 2.2bar at about 35lpm(roughly).

It's a new 25mm pipe . Which is 10 meters from end of drive to house. And a further 6metres to water supply from drive. So 16 meters in total. The old lead pipe didn't have a straight route and may have even been shared.

The house is 3 floors (due to a loft, 6 bed semi of 1962). Double glazing is 10 years old. It has a cavity wall (but looks about 50mm maybe) which has recently been filled with a grant. The outer of the house measures at 8.5m by 9. It has a loft which is insulated. Plan attached of house(the only change is addition of porch and converting the toilet 1st floor to a ensuite, and adding a toilet to main bathroom). First and ground have a height of 2.44 metres.

The pipe work has just been all changed to be optimised and their are 14 rads in the house. The rads are also being changed.

 

[Agile]

At that length it would have been better to have used 32 mm.

I think you still don't understand what is required from the water supply.

 

[mrbg07546]

Lead pipe replacement only supports 25mm with Severn Trent. I appreciate i could have had a joint under ground near the stop tap . But in case the joint leaked

 

[Agile]

The larger tube has lower flow resistance, and costs hardly any more.

The same volume of water has to flow faster through a smaller pipe, hence the higher pressure loss. The shorter the length of small pipe the better!

Tony

 

[mrbg07546]

Regardless of this e water flow and pressure is decent?

 

[mrbg07546]

And anyway that's done! So back to the question.

 

[easyflow]

Out of curiosity why did you state "vailiant"

 

[ServiceNumpty]

Without a heatloss, you're guessing for the right size boiler. As far as cylinders are concerned then there are many options particularly budget based. RM, Telford, Main basic budget cylinders, Oso, Joule, better quality cylinders, or the option is go for a manufacturer package -Vaillant System Boiler, Vaillant Aurostor Cylinder & Vaillant Controls - Or alternatively Worcester System Boiler, Worcester Greenstar Cylinder, Worcester Greenstar Filter & Worcester Control Package which come with 10 years manufacturer warranty.