A forehead slapper(mk)

Mike Kraft

I added a new zone to an existing system yesterday.I added one panel rad and one toekick heater.The fancoil is a Myson and has a low temp (90*) strap on aquastat.The fan coil is in a new mudroom under a shoe rack.The zone panel is on the back wall of the closet.The zone panel also is down feeding the fan coil.

The tees I used are a scoop tee and a mono-flow tee.They are on the return just before going back to the boiler.There is a 13" piece of 1" between these tees.from the zone panel the supply reduces to 3/4" and travels in the ceiling in 5/8" pex.This run is about 18'(one way) where it then ties into an 1 1/4" supply and return manifold.

These manifolds have 4- 1/2" branch's.Each is valved with cu x pex valves.(you still with me?)Three of which are not being used yet.So the only emitter off this is the panel rad.

OK.......the problem is the fan coil wont heat up enough to stay running.It switches on and off.My first guess is the water temp,the boiler is reset and yesterday was approaching WWSD,so I overide and run the boiler up to 150*.Still does the same thing........on,off,long pause(5min) then on,off.No air.......I bleed again.......no air.I am studying the direction of the tees!NOPE!!Everything is right.Keep in mind I am killing alot of time trying to figure it out.I am looking all around at the fan coil,the tees.......I'm stressing out a bit.

I am thinking of draining down and installing a restricting valve inbetween the tees.Anyone know the answer??

The panel had created such a pressure drop that there was'nt enough flow through the loop to circulate through the fan coil.All that was there was a 2'x2' panel rad with 2 short pieces of 1/2" pex looping them.I cut another short piece and added it to my manifolds and BINGO!The toe kick was blowing.

Thought I'd share.

cheese

Alan R. Mercurio

That's Why....

We call you Sharp Cheese. ~

You're are smart dude Brother!

Your friend in the industry,

Alan R. Mercurio

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