This Is No Yoke

I often wondered if there was any difference if the return piping used just one side or was yoked using both boiler tapings in the bottom of the boiler.Mine is piped using one 1 1/2 boiler tap. The other has the boiler drain in it.This boiler is only 80,000 BTU and no bigger than a small end table. What I found using a laser thermometer [measured exact center of each side] was that there was a difference of eleven degrees from one side to the other.The side with the return piping registered 152 deg.The dead side [boiler drain tap] registered 141 deg. My guess would have been opposite. The active side gathers more heat than the dead side.I have to believe it because I saw it. Anyone have a reason? It is a steel boiler so I don't think 11 deg will amount to any destructive force but am still puzzled.When I do the next stoker [if Keystoker ever comes thru] I will make sure they are yoked and then run comparisons.

How long has it been plumbed like that? The dead side is building up mud in the bottom, with no water to transfer the heat the steel inside at the firebox may eventually crystallize from the heat and fail. The reason for two returns is to keep the bellies (both sides) clean. Here is the proper way to plumb return piping. Notice the TEEs with plugs, they are there to allow you to "rod" out the mud periodically. Probably not a crisis, I would wait until spring.

The boiler itself is probably from the 80's but has only been in use for three years.I got it new old stock after the company went out of business in the early 90's but never did anything with it. The drain valve in the dead side still flows freely with clean water so I don't think he is mudded up.I will know when I take it out of service. Regardless of the reason if my Keystoker ever comes in I will be certain to have my tees in position to rod out if that would ever become necessary.Nothing like having fun with hydronics in the winter months.I love it !!! Mike