Hot water cylinder venting

[busby]

I recently had a local plumber replace the small hot water cylinder in my attic with a new larger (and taller) one.

The outlet pipe from the top of the old cylinder ran horizontally for about 0.5m and was tee-ed into the vertical pipe that, in its upper half is the vent. The lower part of the pipe feeds hot water to the house.

As the new cylinder is taller, the plumber led the outlet pipe from the top of the cylinder horizontally for 0.5m, then vertically downwards for 0.65m to the original tee on the vent pipe.

Please can anyone tell me whether or not this is safe? I want to add some decent pipe insulation but don't want to start until I'm sure that no changes are required.

Photo attached:

Untitled

• busby
• 6 Jun 2014
• 1

(Sorry that it appears rotated - of course the cylinder is vertical!)

Thanks.

 

[chimpboy]

Why didn't the plumber tee the horizontal pipe into the vent further up,strange. No it is not very safe, you going to have a problem with trapped air in the horizontal pipe leading to poor hot water flow or no flow at all, horizontal pipe is meant to be going slightly up hill as well. i would get him back and sort it out second thoughts get someone else, cheers

 

[busby]

Thanks for replying so quickly.

I guess it would have been more work for the plumber to tee into the correct part of the vent pipe. Above the existing tee, the vent pipe bends to about 45 degrees for a bit before turning back to the vertical. (The pipe can be seen sloping up from right to left in the picture.) It could be more difficult to tee into the sloping part and the section from the top of the cylinder to the tee could be too short (only 0.35m or so).

The hot water flow rate is very good (in the two weeks since installation) and is easily as good as it was before with the smaller cylinder. Thus, the plumbing arrangement does not seem to be causing problems. There seems to be sufficient head from the cold water tank to push out any air.

I was not concerned until I read elsewhere on this forum that the venting must rise continuously after leaving the cylinder.

I don't want to get the plumber back as I'm not impressed with his work.

 

[chimpboy]

It's not good practice to have high spots on ch or hw pipe work, leads to problems, and is a no no on a vent pipe, cheers

 

[ALCPlumbing]

100% cowboy plumbing. As the others have stated this will not allow air to vent properly.

 

[Nige F]

not even close to a plumber - a cyl. is 1st year apprentice stuff