connection to cylinder coil

[danzkadam]

The feed to my cylinder coil starts as 22mm copper pipe but then reduces to 15mm for about half meter before joining the cylinder. As it enters the cylinder it is converted back to 28mm. The outlet is similar, i.e. 28 to 15 to 22. Is this normal? Can anyone suggest a reason as to why it may have been done like this? I am tempted to change it to 22 or 28 all the way but am concerned that this may cause more problems.

 

[HERTS P&D]

The plumber ran out of pipe.

Andy

 

[Hugh Jaleak]

Assuming you have a fully pumped system, a restriction is fitted in the hot water circuit to prevent the lions share of the flow from the boiler going through the cylinder when heating and hot water are selected at the same time. Some reduce the cylinder connections by using 15mm pipe, another method is to fit a gate or lockshield valve in the return near the cylinder, both methods achieving the same aim.

Otherwise there can be a problem whereby the radiators are slow to heat up until the cylinder is up to temp and the valve closes to the cylinder, when the full output from the boiler is then put into the rads.

 

[ianmcd]

it sounds as though you origionally had a gravity hot water system and it has now been changed to fully pumped keeping the origional gravity cylinder

 

[dcawkwell]

The guy was two cheap to buy a 22mm gate valve to balance it up.
You have a 28mm coil that is big and lazy and will take ages to heat up
the cylinder.
Really the cylinder should have been upgraded at the time.

 

[Agile]

Many customers what it done cheaply!

But you need to measure the flow and return temps at the cyl coil!

Tony