HELP! comfort aire hydro air

NEtech

Hey there a little context im a tech relatively new to the field trying to help a buddy out. When I first arrived I found a bad heat relay which was sending continuous power to the zone valve keeping it open. Swapped that out solved that problem. Next only the outlet pipe was getting luke warm I lowered the fan speed Solved that problem. Next the the outlet now getting very hot but inlet still cold. This is the unit for the second floor there is another unit in the basement identical running fine. Swapped zone head actuators FIrst floor still Heats fine. Im stumped

Can the valve be stuck? Is there anyway the valve could get clogged or jam? maybe stay closed even though the knob spins? It seems to be a circulation problem.

Could it be a sign the circ pump is going bad?

HELP

HVACNUT

So it was too much heat (constant flow through  the coil), and now it's no heat?
Did you leave a valve off?
The outlet (from where?) was luke warm but lowering the fan speed solved it? Put the fan speed back. There were no complaints before this.
Now the outlet is very hot (from where?) and the inlet is still cold. To where?
Is the zone valve open? Not the actuator, the valve. 
Is the loop air bound?

SuperTech

That original post was kinda confusing, not sure I follow your troubleshooting process. But it sounds like the loop has air in it. I would try to give it a good purge and put the fan speed back to where it was originally. 

NEtech

Sorry I see how that can sound confusing. 

THERE IS NO HEAT AT ALL.

How can I tell if the actual valve is open? I’m confused about that I swapped actuators and the same problem happened.

So the outlet to the air handler was getting hot. When I lowered the fan speed it got more hot to the point I couldn’t touch it. Inlet to the air handler stayed cold the pipes to both the inlet/outlet I’m referring to is to the hydro coil.

it seems like a circulation problem I already purged the system a bit should I just fill up a whole bucket?

HVACNUT

NEtech said:

it seems like a circulation problem I already purged the system a bit should I just fill up a whole bucket?

Yes. A bucket. 2 buckets, 5 buckets. Whatever it takes. 
Shut the valves on the other zones and purge until there's no air. Pushing through a hydro coil can be tricky because of the breakup into all the channels, as opposed to a baseboard loop.

SuperTech

Are you sure you are purging correctly? What brand of zone valves are you working with? Pictures of everything would help. 

NEtech

These are the zone heads. Okay I’m going there this weekend I’ll purge some more

NEtech

Just above the zone valve there a red tube with a valve I assume turning the zone off then opening that valve would purge the loop

motoguy128

This is on a 2nd floor and it has a basement correct? Do you have 20psi at the boiler? IS the gauge accurate? IS there a auto air vent or bleeder on the top floor at a high point near the air handler? IF not, if may be very hard ot purge?

Strange that it’s hot only on the outlet? Seems like you have ghost flow. Somehow, but the system may still be mostly air locked.

MaxMercy

motoguy128 said:

This is on a 2nd floor and it has a basement correct? ... IS there a auto air vent or bleeder on the top floor at a high point near the air handler? IF not, if may be very hard ot purge?

I have a two zone hydro-air system, and several years ago I noticed a prolonged cool output of the heat vents on the second floor. Within a few minutes, the air would eventually get hotter. There is a bleeder right on the coil itself, and about 30 seconds of bleeding fixed the slow warm up issue.

Years later I replaced the boiler, and even though I have a lot of ball valves to isolate areas (like the whole second floor hot water system), I could not get the hot water to move two feet with the new boiler until I went into the attic with a bucket and bled it out.

NEtech

MaxMercy said:

This is on a 2nd floor and it has a basement correct? ... IS there a auto air vent or bleeder on the top floor at a high point near the air handler? IF not, if may be very hard ot purge?

I have a two zone hydro-air system, and several years ago I noticed a prolonged cool output of the heat vents on the second floor. Within a few minutes, the air would eventually get hotter. There is a bleeder right on the coil itself, and about 30 seconds of bleeding fixed the slow warm up issue. Years later I replaced the boiler, and even though I have a lot of ball valves to isolate areas (like the whole second floor hot water system), I could not get the hot water to move two feet with the new boiler until I went into the attic with a bucket and bled it out.

You are right I found four bleeders 2 on each line top and bottom the unit is horozizontal

NEtech

If I open both on one line does it create a loop? Should I purge one hole at a time? Should I purge them both upstairs then a final purge down stairs?
 

Should water eventually come out of every valve, including the top one it’s horizontal.

MaxMercy

Yes, water out of every bleeder valve when the circulator is running. If there are two bleeders in each coil, use the highest one. I would open one at a time (highest air handler first) and make sure I get a good stream of water (let it flow a while) and make sure the boiler fill valve is working properly. If it's stuck closed, bleeding may make it worse. Your pressure gauge should tell you everything you need to know while bleeding. If the pressure is low or drops after bleeding, give it a thwack with a hammer and see if it responds - it should replace the lost water and pressure fairly quickly.

In my case, I didn't have to bleed the bottom air handler at all after I replaced the boiler. I guess any air in the bottom loop just went straight to the highest point in the global loop: the attic air handler.

NEtech

Sweet I’ll give it a try Tommorow. I’ve also only been bleeding one air handler I’ll do both next time

NEtech

Okay so unfortunately one of the valves snapped in it now I can’t tighten it enough to get it to stop squirting and I won’t be able to get the valve out for replacement this has to be brazed correct?