Expansion tank and calorifier

[Adam1991]

Hi, is it ok to plumb in our expansion tank around 1 metre 1/2 from the calorifier on the hot side? 
 

We can’t fit the expansion tank directly next to or above the calorifier so we’re thinking of  plumbing it in on the hot side on the run towards the first hot water outlet. 
 

Is this ok? 
 

thanks, 

Adam 

[Tony Brooks]

Yes, as long as you are sure there is no NRV between the two, but that would be a very odd and rare boat. FWIW it can also go in the cold side as long as there are no NRVs between the two

[Adam1991]

Thanks Tony 

[nicknorman]

It doesn’t matter hugely but it is better to plumb the expansion vessel into the cold feed side of the calorifier, but after any NRV of course. With an expansion vessel in the hot feed, it increases the amount of cold water that comes out of a hot tap, before the hot arrives - because water accumulated in the expansion vessel will rapidly cool even if it was hot to start with, and then when you turn the tap on the expansion vessel will empty the cold water into the pipe.