Wet Return Replacement Guidance Appreciated

khkiley

Happy New Year!

I will need to have our wet returns replaced. There are symptoms they are clogged, and I suspect one loop is backing up into the main causing the radiators at the end of the main to not heat up. There is also evidence of water coming out of the main vent at that end.

Previous owners removed and replaced sections of the return, leaving a patchwork of old and new, iron and copper piping.

I want to replace the whole thing, install ball valves to isolate sections and also install taps so I can install a hose and flush them under pressure at the end of the season.

What are the guidelines for wet returns ? What size do they need to be ? Are the ball valves a good/bad idea ? Is there a specific type ? What what be used to attach a hose at the feed and drain to flush this out ?

I will have the work professionally done, I would like to know what I should be asking for.

Thanks in advance to any advice.

Kurt

nicholas bonham-carter

You want to have a drain for the wet return, close to the boiler, with a full size ball valve so that debris can be washed out. Hopefully, there is a floor drain in your basement, or a laundry sink. Ideally, there would be a tee and a stop valve ahead of it at the top of the wet return, so some water pressure from a hose could be used to force out any sludge. If you have no drain, then a larger diameter hose could be routed outside the house, and the water pressure applied at the dry return with valve closed will wash it all out.
I am assuming the line runs on top of the floor, so copper is ok below the waterline, and a larger diameter will be less likely to plug up. Put some bricks under it to keep it from touching the floor.—NBC

khkiley

Thank you very much NBC, you've answered all my questions.

Kurt

EBEBRATT-Ed

Size is dependent on the load connected to the return. If you add up the radiators and get the total rating we can give you a pipe size. Otherwise replacement should be based on what is installed now. I would use full port ball valves. Any valve rated for water is ok as it will never see steam

khkiley

Thanks Ed.

The iron that is left and the copper that replaced it is 1 1/4". I have the load somewhere, I'll see if I can dig it up.

Looks like its all copper from the dry return back. Is there a chance T's and a clean out could be cut into the existing copper ? When reading through many posts on the topic it seems it might be difficult to sweat to the existing copper.

Kurt