Unvented with no tundish

emergencyman · Jun 10, 2015

Hi all,

I have recently got a G3 ticket and realise unvented cylinder shouldn't be left in a dangerous condition, but what would you do if you serviced a 200l Megaflow which had no tundish. The D2 pipe ran in 22 straight from temp/ prv to outside over a distance of around 12m. Termination was less than 100mm but no cage.

Main concern is no tundish. D2 was dripping when I arrived ( air bubble gone ). Had it been winter it could have frozen.

I advised customer in writing it needs urgent attention. Was basically told been ok for last 8 years.

Thanks

Best · Jun 11, 2015

Over a distance of 12m in 22mm pipe? And I suppose that doesn't allow for the extra distance for each bend? Highly wrong obviously and dangerous. Although hot water is hardly going to spew out of the tundish as there ain't one fitted! :smile:
No cage over the open ended pipe is also dangerous and a child could get potentially scalded.
Probably the best thing you should have done was NOT service it at all! Just check it all out and refuse to do any work unless they authorise you to fix the faults. After all, the unit cannot be serviced properly if you have to leave those serious faults.
If you mentioned all 3 things in writing you did well, but I would have also turned off the water to the unit and any heat sources - electric immersions or gas/oil and give that in writing to say you did this for safety and advise it not to be in use until all 3 points are rectified. Also do this by email and texts and a further letter so you have complete paper trail of your concern and advice. To hell with them if they just turn it all back on again, - you have done your bit and covered your bum.
Tbh, a lot I see are badly wrong. Funniest one was a D2 pipe reduced at tundish to 15mm and just stuck out of outside wall on house upper floor. To make matters worse the pressure relief valve had a lever valve screwed into its outlet! Thank goodness I wasn't working at it, but merely commenting on the install to the customer.
You should give the customer a link to Mythbusters video of exploding unvented cylinder when they say it has been ok for 8 years.

GrahamM · Jun 11, 2015

No tundish? Thats nothing!
Come back to us when you get one with no wiring ie. no zone valve or thermostat control and D1 D2 ran straight through in 15mm. :lol:
Done all you can do really. Cover yourself in writing.