Unvented Tribune Cylinder

[bigcheese]

My mate has been working on an unvented cylinder today (not sure if he has his ticket) and has asked me a few questions about it. I'm not that experienced with unvented so I thought I would ask you guys.

The cylinder is a Tribune 210 litre capacity.

It is a straight like for like swap. The old one had no expansion vessel, but the new one came with one. He decided not to fit it as he said that the cylinder takes on the expansion within the cylinder. Is this right??

 

[so-solar]

the manufactures instructions said.......................................?

 

[Puddle]

You get internal expansion chambers and external ones,do the same job,obviously if same size cylinder and expansion vessel external,cylinder will have larger capacity for hot water storage

 

[PlumbBobBob]

if the cylinder came with an expansion vessel it must be fitted.

 

[Bernie2]

Agree with posts. Some have internal expansion space and some have an external expansion vessel fitted.

Same idea different way of doing things.

 

[John Flower]

Naughty not being qualified and fitting one of these. Unvented cylinders fitted badly are potential bombs waiting to go off.

 

[bigcheese]

I agree with you guys. I would have fit whatever came with it but I would have thought it is safe. The old one was a similar cistern and didn't have one fitted. The heating was on a S plan with F & E tank in the loft. I would have thought if the pressure increased dramatically it would release out the blow off.

 

[samwilko]

The expansion vessel is vital and must be fitted. Absoloutely must. They wouldn t send it otherwise.

 

[Puddle]

The secret is not only 'fitting what comes with it' but also knowing why you are fitting it and what it is for

 

[samwilko]

Exactly. Unvented requires a seperate qualification for a reason. They MUST be done correctly.

 

[bonesy60]

The f+e tank will be for heating only if it's an unvented cylinder then there is no vent so it needs an expansion vessel.

 

[Puddle]

The f+e tank provides the water supply and ventilation requirement for the a open vented boiler
The boiler will do the heating but also, it may heat the hot unvented water cylinder through the cylinder coil, the same as an open vented cylinder
I say may, because it is possible the unvented cylinder is heated by immersion heaters only
If heated by boiler it is also important to wire motorized valve through the high limit thermostat on cylinder
The main storage tank supplying the cylinder is what is replaced with an expansion vessel
When you fit any appliance and think about its operation you should forget about any safety devices that are fitted, the appliance should work perfectly well with the use of normal controls and not use any safety devices
The safety devices are just there for safety and to protect equipment and should not be used or have to be used in normal operation
That is why over heat thermostats are manual reset, to stop them becoming used on a regular basis if normal thermostats fail
So to say, if pressure gets to great pressure release valve will work is not acceptable