Replace SE duct boiler-

[Ted808]

I've been asked to price up for replacing an old Halstead F50 system boiler and unvented cylinder. I'm sure it will be a pandora's box. Have yet to take a look but any advice welcome, pionters to look for and suitable replacements. I've seen Vokera do a suitable but not keen. Will do more research if I have time. Cheers

 

[firemant]

I've been asked to price up for replacing an old Halstead F50 system boiler and unvented cylinder. I'm sure it will be a pandora's box. Have yet to take a look but any advice welcome, pionters to look for and suitable replacements. I've seen Vokera do a suitable but not keen. Will do more research if I have time. Cheers

Would love to help. But I have never seen an actual SE duct. Or a U duct.
After nearly 45 years in the game, I was beginning to think they were a myth

 

[ShaunCorbs]

I’m not 100% but I might of read something a while ago you can’t fit any new boilers to se or u ducts

Gas safe would be the best to ask

 

[AMGasServices]

We look after a few se duct. We have all standard efficiency boilers installed in them. Nothing condensing. Due to the layout but installing boilers on external walls.

 

[Gasmk1]

From what I am reading it has to be a C2 type boiler so you will need to find which ones are suitable.

 

[firemant]

This is all covered on the ACS, but I must admit that I just go through the motions as I am never likely to deal with them. But do I recall correctly that you cannot use power flues on a SE or a U duct. Or one of them. ?

The turbulence would upset the principle of operation?

 

[Millsy 82]

I've only ever seen 1 a lad condemned the boiler and then I got sent in. As firemant said when it comes to it i just glaze over as I didnt think there was any round me. It was a case of scratching around in the van for my book and phoning gas safe as this was before mobiles with internet.

As the boilers were being replaced though they were being moved to external walls.

 

[firemant]

Did a quick google and TB 123 covers this, but could not find the latest one as I struggle on phone

 

[Ted808]

Thanks, the general guidance seems to be that they shouldn't be replaced unless you can inspect the whole of the flue- maybe in the future by a drone as in person it would be impossible. This is based on the new flue in ducts/voids reg's. The other point I found is that condensing flue gases are not as hot as regular boilers. That also affects the performance of the flue as a whole. Basically, I'm going to recommend an electric boiler for heating the existing rads and continue with the immersion cylinder for hot water. What do you think? DO I now need special power supply and an electrician?

 

[ShaunCorbs]

Depends on the load / appliances

 

[firemant]

Thanks, the general guidance seems to be that they shouldn't be replaced unless you can inspect the whole of the flue- maybe in the future by a drone as in person it would be impossible. This is based on the new flue in ducts/voids reg's.

Do you mean the appliance flue, or the SE duct?

Anyway, there are 2 things:

“A condensing appliance shall not be fitted on a shunt-duct, SE-duct or U-duct system” [IGEM UP-17, Clause 6.1.4]

and

I am not entirely sure about when this comes into force, but there is/will be a ban on new or replacement boilers currently available fitted in buildings which have a total height of 18 metres. To do with the flue being plastic.
Although this may only apply to student housing and hospitals.