Hi all! I'm hoping to get some troubleshooting advice on a Myson Whispa II hydronic kickspace heater installation I did. (I'm not a plumber, but was very careful to follow the Myson installation instructions).

Here's the problem: When the heating is on, all baseboards work fine, but the KSH will not cycle on.

Background: Single loop system, KSH is first unit on the loop, others are all baseboard. I installed a Venturi tee on the supply side and regular tee on the return. I tested that the fan and aquastat do indeed work on the unit (jumping the wires for the fan, and heating the aquastat both turned the fan on - so the unit itself is not at fault). I bled the unit from the front of the unit and water does squirt out in a steady stream (starts out cold and then becomes hot). The pipe on the unit that the aquastat is soldered to does not get hot, which I'm assuming is why the aquastat doesn't turn the fan on. Why would hot water running through both the supply and return hoses (both get very hot), but not through the unit? Any ideas?? Could I have installed the Venturi tee wrong? Would that cause this problem?

 

Probably still air in the heater. You need to bleed from the high point to remove the air.

Another approach is to install supply and return isolation valves and a hose bib upstream of the return isolation valve. Shut the return and open the hose bib to get a fast flush through the heater.

Kickspace heaters can be difficult to bleed.

 

The venturi tee should be on the return side, the regular tee on the supply side.

 

Not necessarily. A monoflo tee can be installed on either the supply or return, but the arrow (if there is one on the tee's body) will point opposite depending on where. If your tees have rings on one side, the rings should be in between the risers serving the heater.

To increase flow diversion, you can install monoflo tees on both the supply and return, but of course, one will be pointing one way and the other the other way.

But there is no way to know if he installed the tee correctly based on the info given. Looking at the inside of the tee (before installation) makes is pretty obvious which way it should be installed - either for a supply or return.

 

Thanks very much for your reply. So do you think screw for bleeding at the front of the unit is insufficient (the high point in this setup) to get the air out? I let it bleed into a cup for a good minute or so. Still no joy.

 

The tee is indeed the type Mike refers to - installed on supply side with arrow facing in direction of flow. The supply and return hoses both get very hot, so there is flow, but from your responses, it seems that there's either air in the unit or the pressure is insufficient with only the one tee. I guess I'll try to flush it as suggested before changing out the return tee. Thanks! Obviously, I'm not an expert, but I WILL get this right if it kills me.

Also, I'm a "she" not a "he"... but don't hold it against me. Rebecca

 

but here's a pic for reference.

 

Many thanks, NJTrooper. Not late at all.

 

If there is just one arrow (and no indication of either "supply" or "return") it is probably indicating the direction of flow in the main when the tee is correctly installed at the return. That was the nomenclature that Bell & Gossett initially used decades ago (the originators of the monoflo system). If that is the case, then your monoflo tee is installed backwards.

I see two choices to answer the question for sure - drain, unsolder, and remove the tee and inspect its internals. Or, go look at a new tee of the same brand, and inspect its internals.

Also, how far apart are the two tees? The more the better for maximum diversion. Ideally, at least 2-3 feet or so.

I'm assuming that your kickspace heater is located above the main that you're tying it into. If it is below the main, then you do need two monoflo tees, one on the supply and one on the return. Also, if your piping run is long between the main and the heater, I would opt for two monoflo tees.

If, as you say, you get water from a high-point bleed in the heater, then I'd agree that air must not be your problem. A backwards tee could be it.

Could you link us to photos - one, a close-up of the diverter tee, and one wide-angle showing both tees, etc.?

P.S. Another thought. Since you used hoses for the hook up, maybe you can disconnect the hose from the monoflo tee - and peek into it and see if you can determine if the venturi orientation is correct.

 

I see hoses mentioned in this installation, are they large enough? they should be at least as big as the piping, or that could be a cause of a flow problem, and are they temperature rated.
Sid

 

Ok, I have a photo but cannot figure out how to upload it on this forum. It says I cannot add attachments. Help, moderator!

Today, I reversed the setup: The venturi is now on the return side, (the tee has both "supply" and "return" arrows on it, but I figured if return-side is the most common practice, I'd do it) and the "Return" arrow is pointing upstream - is that correct?). Fired up the system, both hoses hot (like before, pretty much), bled it a very long time and...

No joy

The tees are exactly 12" apart (as spec'd in the Myson installation instructions). The kicker is about 10" above the main. The hoses are 1/2" and came with the kicker. It's so frustrating

I think the tee may be backwards, as you suggested. Should the arrow always be in the direction of the flow? I.e. the the "return" arrow should point downstream?

 

No, wrong again. Please look at the diagram that Trooper posted.

When the tee is installed at the return, the arrow labeled "Return" should point in the direction of flow (downstream). If the tee is installed at the supply, the arrow labeled "Supply" should point in the direction of flow (downstream).

Examine the internals of the tee, and see if you can tell how it works. Then it might all become clearer.

You can't load pix directly to this site. Post them on a freebie image hosting site, and copy the link here. Google "free image hosting," and you will find several such sites.

 

I've posted a photo at:



I have changed the setup and now it has two monoflo tees is plumbed exactly as shown in the diagram posted by NJTrooper (thanks, again!).

Even with this set up, the only way I have gotten enough flow to the unit to (briefly) turn on the fan, was by closing the slotted ball valve on the return hose completely and bleeding the unit until very hot water came out. But, after closing the bleeder screw, the fan soon cycles off. So this leads me to think that there is air somewhere in the system which keeps the flow from being sufficient even with the monoflo tees. PSI is 12 and temp 180 on the boiler, but maybe needs to be bled more?

Would adding a ball valve somewhere on the bypass help to regulate the flow (to force it up into the supply?) If so, where should I put it exactly?

Sorry to be a PIA, I REALLY appreciate your help, patience and insights.

 

That's bizzare... you should have plenty of flow through that kicker...

I have one final suggestion: replace that sharkbite coupler between the two tees with a ball valve. When you close the ball valve you would/should have the full flow of the system forcing water through. Once all the air is out, open the ball valve again.

I think someone mentioned that there is a lower temperature thermostat available that turns the fan on at a lower temp? That _might_ be an option also.

Is the blue tape just to ID the return side? or is that hose 'kinked'?

 

Ok, will do. Blue tape was just to ID return hose when I was installing (no kinks). Thanks! Rebecca

 

Several points here:

1. The fan's not coming on may not mean that flow isn't getting to the heater. I'm not familiar with Myson, but the standard aquastat that comes with the Beacon-Morris kickspace heater is set too high for the fan to come on in some systems. (They will send a lower-temp aquastat if requested. Maybe Myson will too?) You could temporarily jack up the boiler temp to, say, 200 deg, and see if the fan starts acting normally.

2. I assume that you can get access to the heater internals through a hatch in the bottom of the cabinet? See if the coil in the heater is getting warm/hot. If it is, then you've got flow, and it must be the aquastat -- and there isn't an air problem or a kinked hose.

3. Your idea of putting a ball valve in the main between the two monoflo tees is tempting - you could throttle the valve and force more flow thru the heater. BUT, it may upset the flow to other heat emitters on the same main. Don't do this until all other avenues are explored.

4. If you want a foolproof way to bleed the heater, both now and in the future if needed, I see an easy way to do it. Look at the slotted ball valve at the return. Disconnect the hose, and screw a street el into the valve (the el will give you more working space under the subflooring, and resolve your hose kinking worry.) From the street el, go to a tee between the el and the hose connection. Off the tee, install a hose bib. To fast flush, shut the return valve and open the bib. This is all easier done than said.

5. That return hose could be kinked, which might explain why you get heat when bleeding. Install an el to provde more room so that it will not be kinked. And/or remove the blue tape so it can be inspected. Check the hose connections at the heater, too, to be sure there is no kink there.

6. I admire your soldering. Well done.

 

Yeah, I meant to kudo the soldering too! ... and all this time I thought the solder was SUPPOSED to go 2" up the pipe from the joint, and form a big blob on the bottom!

Just to clarify, what Mike said, the ball valve between the tees is for bleeding purposes only, at all other times, wide open.

 

Thanks! I'm blushing. Every girl appreciates having her soldering admired.

I'll follow the advice with fingers crossed. And hopefully won't be bugging you too much more.

 

I think you're homing in on the solution. Keep at it. Go slowly, one step at a time.

I was going to invite you to come and do all my soldering, but my wife said No.

 

I can't be sure from the pictures but it appears that at least one of the hoses, and maybe both, rise from the main connection and then drop down before rising through the hole in the floor. If so, this is your problem. You may be able to install 90 degree elbows from the main and then to the hoses to cure this problem.

 

Ok, I was so frustrated. Tried everything. Finally, out of desperation, I swapped the hoses (supply on return, return on supply), filled the boiler to about 20 psi (thinking it might help to have more water in the system to increase water pressure, shut the valve straddling the bypass, and bled the unit for the umpteenth time.

It worked.

At the end of the day, I tested it again before I left and forgot to close the valve (it was wide open), and

It worked.

Either I am a dope (which is quite possible), or the circulator is pumping backwards somehow, or I am a knucklehead. I swear to our dear Lord that I traced the supply and return pipes, and when I fire up the system, the hot water is definitely being pumped into the supply side of my photo (I can feel the pipes gradually get hot going in that direction).

Anyway, I want to thank you all for your insight, input and willingness to not treat me like an idiot.

Many, many thanks. Rebecca

 

If Rod Serling were still alive, he might make this saga into an episode for Twilight Zone.

Just swapping the hoses (and not the tees) shouldn't have made much difference. Either way, the water would be diverted through the coil on the kickspace heater, right?

Maybe by swapping hoses, you unkinked something? Conceivably, you finally got all the air out of the heater, once and for all?

Maybe the water was running through the heater coil backwards - and the fan aquastat, being on the coil's 'inlet' - well, you see, the water might get cooled before it reached the aquastat? And then you flipped the hoses, and the 'stat and fan started working?

But, I do know from experience that getting all the air out of a kickspace heater can be tricky. If you ever have to drain your system, first shut those two slot-operated iso valves for the heater - bottle up the water in the heater. And don't open them valves until the system is refilled and air is bled out of the rest of the system.

We have a kickspace heater that blows on the floor toward our kitchen table. Nothing nicer that feeling that warm air blowing on your feet and ankles during a frigid morning's breakfast. Really doesn't make that much difference about the overall room temp - if my feet and lower legs are warm, I'm happy!