Creating a bypass loop before cylinder

[notfocused]

Hi,

I am going to add a Cylinder stat to my heating setup and could do with a little advice, i currently have one motorized valve to control my central heating and i want to add another to my hot water circuit to be controlled by the cylinder stat.

The flow and return into my cylinder is 3/4 inch pipe,I live in Dublin so we use 1/2 inch, 3/4 inch and 1 inch pipework here to avoid any confusion !! I am thinking of putting the motorised valve on the flow just before the elbow into the cylinder, to then create a bypass loop do i put i a 3/4 tee just before the motorised valve and run 3/4 inch pipe down to the return and tee into that ? do i add a gate valve to this pipe and leave this slightly open or add a automatic by pass valve ? what would be the ideal set up.

Any help greatly appreciated

Thanks

Paul

 

[Agile]

Take care before you create a dangerous situation!

Is yours a sealed system? Whats make and model of boiler?

Does it have a feed tank in the loft? If so you will need to take very correct advice to ensure you dont put a valve where its going to create an unsafe situation.

Tony

 

[notfocused]

Hi Tony,

Yes its a sealed system, there's only one tank in the attic that feeds the cold water to the cylinder/shower etc.
The boiler is a Ferolli optimax HE31S ( System Boiler )

Paul

 

[Agile]

OK then in that case you should be able to put a two port valve anywhere that you find convenient.

Cylinder stat should be about 2/3 of the way up the distance between the heating coil connections or about 1/4 way up the cylinder if the coil is low down.

Tony

 

[notfocused]

Hi Tony,

Thanks for the help, going back to original post would the bypass loop connections i have suggested be ok ? what would be the best type of bypass to create a slightly opened gate valve or a automatic bypass valve ?

Paul

 

[Agile]

A proper automatic type are the only recommended ones.

There are a few differeing views. Some put it across flow and return before the motor valves. Others put it across the HW motor valve so the heat bypassed is used to heat the cylinder in theory.

I usually put them across flow and return as its easier to pipe them that way in most cases. Probably better on HW cylinder if thats possible.

Tony