Vaillant 630 bypass question

[Frog67]

Evening all i have a technical question i hope you can help me with.
I've been asked to quote to fit a Vaillant 630 system boiler on an S plan with 3 seperate zones, 2 x CH and 1 x HW

The system comprises of 14 rads and a 42 x 18 indirect cylinder
8 rads on ground floor (1st zone)
6 rads on first floor (2nd zone)
Total rads output = 24kw
The 630 has a built in bypass but should i still fit an external one?.
I'm concerned about an additional bypass causing circulation / cycling problems if the built in one opens as'well as an external one.
Thanks

 

[Harvest Fields]

I do.

 

[Last Plumber]

Evening all i have a technical question i hope you can help me with.
I've been asked to quote to fit a Vaillant 630 system boiler on an S plan with 3 seperate zones, 2 x CH and 1 x HW

The system comprises of 14 rads and a 42 x 18 indirect cylinder
8 rads on ground floor (1st zone)
6 rads on first floor (2nd zone)
Total rads output = 24kw
The 630 has a built in bypass but should i still fit an external one?.
I'm concerned about an additional bypass causing circulation / cycling problems if the built in one opens as'well as an external one.
Thanks

I definitely would do yes.

 

[Last Plumber]

The one in the Boiler is not big enough in my opinion.
Not for an S plan anyway.

 

[Frog67]

I do.

Thanks, i must admit that not fitting one on an S plan doesn't seem right but the MI's state that an external one isn't required

 

[Last Plumber]

Thanks, i must admit that not fitting one on an S plan doesn't seem right but the MI's state that an external one isn't required

I know but I think it's best practice.

 

[Harvest Fields]

You wouldn’t get told off for it but for the sake of £30.00 and no call backs.

 

[Frog67]

Thanks fellas I'll go with your advice

 

[chris watkins]

Can any one tell me why you need an external bypass with an S plan with a 630?

 

[Last Plumber]

Can any one tell me why you need an external bypass with an S plan with a 630?