No Flow through Kickspace heater - Help!

refields

We replaced an existing slant fin heater with a Beacon Morris K120. 

Connected supply to supply and return to return which are fed by a single header off a one hot water pipe loop. 

Installed a new air vent off the return right by the new heater per the manual. 

Existing return line appears to have scoop tee and some a balancing valve. 

When I refill the system I initially hear air bleeding through the air vent until it fills but no flow through the new heater.  

The baseboard radiator worked fine previously. 

Thoughts? Help!

Photos:

supply off header
return off header 
New kick space / air valve

refields

refields

Larry Weingarten

Hi, Is there an existing way of bleeding all the air from the heater and piping? It may be air-locked, even with that air vent... Could you put a valve under the vent, then temporarily hook it up to a hose to bleed it, then replace the vent?

Yours, Larry

STEVEusaPA

That won’t work without at least 1 or 2 monoflow tees, or its own circulator.

mattmia2

I think the air is going to migrate to the top of the coil and the supply, either purge it as larry suggested or put a manual vent on that supply. The monoflow isn't going to be able to purge enough air to get flow started.

Unless there is any particular reason it needs the flow in that direction, if you swap the supply and return at the riser connections it might just all bleed out the automatic vent.

Big Ed_4

Instal a purge valve set up one of the risers in the basement to purge the air out of the unit . A shut off valve to cut off the tee and a drain valve to purge out the unit . You can now pull out the float vent before it leaks ....

refields

Thank you all for the suggestions. There is unfortunately no way of bleeding from the unit itself that I am aware of. 

To me It doesn’t make sense why the manual has the air vent on the return, which is lower down than the supply.  Especially if the problem is that it is air locked in the higher coils which makes perfect sense to me. Any thoughts on why this would be?

im thinking I will start with trying the following (in order of least work):  

1. Putting a valve under the vent to manually bleed it. maybe this will increase the flow sufficiently to purge the air?

2. if that doesn’t work, solder in a new tee and move the air vent to the supply side. 

I’ve had a really hard time disconnecting the rubber hoses from the hose barb without damaging them so I’m trying to avoid doing that if possible. 

Paul Pollets

Are the two tees feeding the unit 12" apart? Is the monoflow tee on the return? The air vent should also be on the return immediately adjacent to the unit. Sometimes 2 monoflow tees are needed, as suggested by Steve. I'm not a fan of rubber hoses on hydronic systems.
See page 5 of the installation manual:
https://s3.amazonaws.com/s3.supplyhouse.com/product_files/Beacon-Morris-K120-Install-Instructions.pdf

mattmia2

If you use some channelocks or pliers to slide the constant tension clamp off, you should be able to slide the hoses off by pushing from the end of the hose off the fitting. If you pull it is like a chinese finger trap and will tighten up on the fitting. Sometimes a small screwdriver helps but be careful not to gouge the fitting.

I would put manual bleeder valves on both supply and return since you won't see that automatic vent inside the cabinet when it leaks. Or keep the cap tightened once it is bled.

refields

The supply / return tees are 22” apart. The supply tee has an arrow on it pointing in the direction of flow on the header. The return has no arrow on it.  I’m a little worried because with no arrow on it, I can’t be sure whether the return tee is mono flow or not and which direction. Also from what I read in the manual of a supply mono flow tee is used the arrow should be opposite flow. 

This is the same exact condition that exists on all the connections between all other baseboard heaters in the house, and they all work fine mind you. 

Any thoughts on what maybe going on? Each of the return lines also has what appears to be a balancing valve. 

Big Ed_4

You are thinking too much ..... You have a air pocket , get it out

refields

Fixed! I installed a ball valve purge point which cleared the air lock. I’ll just use this with a washing machine hose below the kitchen sink as the “air vent”. Thanks for all the suggestions!

refields

Big Ed_4

You can remove all that crap now

refields

If I remove all that crap what will I do when the system gets drained down for service and airlocked again after the sink is in haha?

Larry Weingarten

Hi, A thought is simply to remove the automatic float vent and replace with a manual vent. This could allow you to service it without the risk of an automatic vent failing and leaking all over. The automatic vents just do fail with time. Or you could just remove the vent, plug that line and use the ball valve as your non-automatic vent.

Yours, Larry

retiredguy

To get the maximum heating capacity from that fan coil both the inlet and the outlet (supply and return) should have Mono-flo tees installed on them as @Steve suggested. Those Beacon Morris kick space heaters probably have a lot more resistance to water flow than the unit they replaced. You can always reduce the flow using that manual balancing valve although it looks like it should also be replaced. My 2 cents.

Ctoilman

No way I'd leave an automatic air vent under a counter, they ALL will leak at some point.  Just leave a valve if you want to keep a purge point.

Tom_133

Didnt read all the comments but couldn't you have just put a ball valve between the two tees feeding the unit, so you could close it, then purge at the boiler? Then it would be full of water, no air, and then simply turn on the valve after purging. Good to get rid of that hyvent, it WILL leak sometime.

refields

Thanks for all the follow up responses (except for one that would have been a really bad idea - ha just busting your balls big Ed).  The knowledge here is awesome and I’m very grateful. 

I found that neither the automatic spirotop vent nor the manual taco vent in the last picture were sufficient to clear the air block. What worked perfectly was the ball valve. So I am just going to leave this under the sink with a washing machine hose to purge if ever needed in the future. Thanks Larry, Matt and Tom for that suggestion. 

As for flow / heating capacity, its fine as it is so I’m not going to mess with installing an addition mono flow tee or bv now but it’s good to know that is an option.  

Kind of sucks I have that extra $70 spiro top laying around now. Maybe I’ll stick it on the main hot water loop in the cellar by the boiler at some point to remove any air that somehow gets in the system?

Big Ed_4

If you instal a purge valve set up on the riser leading up to the kicker heater you can purge all the air out in the basement with a hose and bucket . All the air purging stuff that was added above are not needed . Your not breaking my balls , I don't have problems with kicker heaters ....