Does a WB 29cdi combi need a dump rad?

[alan333]

Hi,
Should a Worcester Bosch Greenstar 29cdi Classic combi boiler require a 'dump' radiator? The bathroom towel rail has a pair of lockshields on it, elsewhere there are TRV's.
Thanks

 

[lightning]

No

 

[alan333]

Thanks mate, I didn't think so

 

[boilerdoktor]

Always best practice to fit a bypass when the boiler doesn’t have one. Or an uncontrolled rad
And the cdi classic doesn’t have one

 

[alan333]

So it needs a dump rad then?

 

[fixitflav]

So it needs a dump rad then?

Not in addition to your bathroom towel rail, I wouldn't think. That will act as your dump rad, as long as nobody closes either of the valves.

 

[boilerdoktor]

It will need one, what if the rad is turned off in summer

 

[fixitflav]

It will need one, what if the rad is turned off in summer

If it were me I would have a roomstat, either in the bathroom, or in another room without a TRV (or open the TRV fully, or remove the actuator). That would be a common setup, but he didn't say whether he has a roomstat or not.

 

[ianmcd]

If it were me I would have a roomstat, either in the bathroom, or in another room without a TRV (or open the TRV fully, or remove the actuator). That would be a common setup, but he didn't say whether he has a roomstat or not.

you would have a roomstat in the bathroom ???

 

[fixitflav]

you would have a roomstat in the bathroom ???

OK, probably not, Plan B!

Or make sure nobody does turn the rad off. What's the point of a lockshield valve that can be closed? (except in special circs, eg maintenance). And the handwheel should be removed, if it's not a special valve needing a key, to prevent unwanted closure.

 

[alan333]

Thanks guys. Perhaps I should have been clearer with my question. I meant does the system require a dump radiator at all - currently the bathroom towel rail acts as one since it has lockshield valves with covers on them and is permanently on. You've answered my question that it does, but not a radiator in addition to the towel rail.
Thanks

 

[bazdaman]

Is there an automatic by pass on the system?

 

[alan333]

Is there an automatic by pass on the system?

I don't know, perhaps the boiler has one fitted from the factory, perhaps not - hence the thread.

 

[bazdaman]

Not one in the boiler as stated above. Google auto bypass valve it goes outside the boiler between flow and return.

 

[alan333]

Thanks again. The actual reason for the thread in the first instance is that I've temporarily isolated and removed the towel rail to repair the wall behind it. I've said to ensure that at least one radiator is fully on if the heating is being used in the meantime, but it got me thinking.