Hydronic radiators (Myson), one not heating, OWB with TACO pump

[monkeyratmom]

Seven years ago installed a Central Boiler 5036 and Myson Radiators. Love the Boiler. Love the radiators, but last year the kitchen radiator didn't want to heat up and now one of the two in the den. Pins aren't sticking. Is the only other recourse to flush the system? The kitchen didn't bother me much, cook something and you wouldn't even notice, but I want both my radiators in the den to work because sometimes I just want to roast myself . This is a closed loop with a TACO pump set up that has worked great all this time. Corrosion inhibitor added at time of installation. There is no air in the system, and hasn't been since installation. Really don't want to do this, I can't imagine it not being a(Admin language edit). And it's cold outside.

[trapper]

check the impeller in your taco pump.  they deteriorate and loose pressure and flow.  I have to change mine every couple years.

[thecfarm]

I was going to say pump too,mine go every few years too. But,you said the one in the kitchen stopped working,but the den ones was fine. I can feel my lines coming in and can tell if the pump is not working as well as it should. A copper line at 180° is hard to hold on to,it's hot,the plastic line can be tolerated.

[Corley5]

  We had to replace the pex-al-pex in the old part of the house this fall.  The last couple winters the system wasn't heating like it used to.  Inspection revealed that the inner layer of pex had separated from the aluminum causing restriction.  We replaced it all and fixed the problem.  We think the cause of the failure may have been an overheating event a few years ago :-\

[E Yoder]

How are these plumbed and controlled? Homeruns to each rad from a manifold? TRV? Just trying to think through the possible problems.

[monkeyratmom]

Well, life's been a EDITED BY ADMIN lately, so haven't been back for an update. Haven't been able to move past my first step, bleeding the radiators.  They all needed bleeding, except the ones not working. Unfortunately, the head of the set screw on one of the radiators in a bedroom is so damaged I can't get a grip on it to turn it.  The pump is fairly new. We had to replace it in 2015 because it got boiled, basically .

So, how do I fix the screw head when it is so hard to get a grip on and a flat head screwdriver can't make it turn. And why are they so soft anyway? They are so not idiot proof .

[monkeyratmom]

P.S. I misspoke when I said there is no air in the system. There was no air in the two non-working radiators. Didn't even think about checking the rest of them until someone mentioned it. They all needed bleeding.

[Roger2561]

Well, life's been a EDITED BY ADMIN lately, so haven't been back for an update. Haven't been able to move past my first step, bleeding the radiators.  They all needed bleeding, except the ones not working. Unfortunately, the head of the set screw on one of the radiators in a bedroom is so damaged I can't get a grip on it to turn it.  The pump is fairly new. We had to replace it in 2015 because it got boiled, basically .

So, how do I fix the screw head when it is so hard to get a grip on and a flat head screwdriver can't make it turn. And why are they so soft anyway? They are so not idiot proof .

I have one those units in my kitchen too.  I too have damaged the bleed screw without trying.  The way I figured out that it was air locked was the copper pipe feeding the rad was so hot it hurt to touch it but the return line was cool to the touch.  As soon as I was able to bleed it I couldn't touch the return copper pipe without burning myself. 

I believe the bleed screw is made of brass so it doesn't take much to damage it.  I don't know what to answer you regarding fixing it other than removing the damaged one and see if you can find a bolt that you can grip the head with a nut driver.  I would use the same metal they used when they made the unit.  Roger   

[monkeyratmom]

How do I get that screw out without making a huge mess. I don't want to get water everywhere.

[Roger2561]

Are all of the rads on the same zone?  If not, perhaps you can isolate that zone, with no water running you shouldn't have too much of a mess.  If you know the size of bolt needed, have it ready to go so that as soon as you remove the old damaged one you can quickly replace it with the new one.  Roger