I Need Some Ideas

The stoker has been on for a while and keeping the set point right on the button, and then all of a sudden the temp started creeping up in the house.It now maintains 81 degrees 24/7. The condition I have is that both Taco model 220 1nd 218 flow checks seem to be hung open. The boiler maintains 160 degrees and this system seems to heat very nicely on gravity. I have cycled the circs and taken a small ball peen hammer to the top and sides and bottom of the flowchecks. I am reluctant to rip them out right now with the cold front coming in and the parts houses closed for the weekend. What else did I not do to try to resolve this strange twist of mechanical mischief? They have been in service 14 years. Thanks for your thoughts.. Mike

Some flow checks have a cap or plug on the bottom. If so, shut the water off that feeds the system, bleed off the pressure and then remove the cap/plug and empty the mud. Over time, the mud builds up and they can't close. They should actually have a short drip leg to collect the sediment.

CS, These have 3/4 inch plugs in the bottom. I did not realize that one could access the workings,rather I thought that was just another piping option. Thank You Mike

Mike,

A 4" piece of pipe with a cap makes a nice "mud leg". The 4" piece will hold more that a close nipple. The 4" nipple also gives your pipe wrench something to grab.

Flow check with "mud leg". -Don

stovepipemike wrote:CS, These have 3/4 inch plugs in the bottom. I did not realize that one could access the workings,rather I thought that was just another piping option. Thank You Mike

It is another piping option that eliminates the need for a drip leg! Ah ha ha ha ha ha!

I got the bright idea that I would like to have some extra gaskets in case I have to cycle the stem and lift the shaft manually for gravity flow sometime or this unit sticks on me again. We all know that when one exercises a sleeping piece of hardware with 15 pounds of water pressure on it, one is often just plain asking for a series of rabies shots after being bitten. Long story made short I was told that the sealing component in the stem of the Taco's are not field replaceable. I was further told that to remove the guts [new interior]and leave the body in the piping is almost as costly as buying a whole new valve plus the guts are not readily available anywhere. I will get myself a entire model 220 and model 218 just to have in case I need to field strip the insides out. What a way to sell more valves Huh ?? Mike