We have a hot water system with one pump and three zones. The house was built in the 70's and the heat system might be original. Today the zone for our living room and kitchen stopped getting heat. There also is central air on this and one other other zone. The furnace runs, and the other zones are getting heat normally.

The thermostats are the standard, round Honeywell with mercury. The transformers are also Honeywell.

I have a multimeter. Is there a way I can test and see if the thermostat or the transformer is the problem?

Thanks,

Jerry
St. Peter, MN

 

Jerry, since you say there is central air ... I'm thinking that you have 'hydro air' ? where there is a heat coil in the air handler?

In other words, it's forced hot air, and not baseboards, right?

(not that it makes any difference in the troubleshooting, just curious is all)

What zone valves? Do they have terminals, or lead wires?

When you turn up the thermostat for the zone that doesn't heat, does the pump run and the burner fire?

If it does, can you feel the pipes getting hot going to the the air handler? and cold on the return pipe?

Take a look at your pressure gauge on the boiler... tell us what it reads, and at what temperature.

 

Our system is a little strange. It is hot water with baseboard heat. Then it also has ductwork for the air conditioner. I mentioned the A/C in case it made a difference with the wiring.

The guage is in a very awkward spot to see, but I did get a picture.



It looks like it is at about 200 degrees with a pressure of perhaps 4. I honestly do not know what the pressure is supposed to be. We have been in the house about five years, and had a problem with the pilot light last year, but otherwise it has been trouble free.

Nothing seems to happen when we turn up the thermostat for the zone that is not working. However, the other two zones have heat.

I'll post some more pictures.

 

The Boiler and Pump


It is embarrassing to show how little I know about my heating system. Just take it for granted until there is a problem. There is one pump, and I think these are transformer valve assemblies controlled by the thermostat. If I am wrong, please let me know.


Here is the bottom of one of them. I think this is for the basement and may not have the wires for the air conditioning. The others have so many wires that it was not easy to get a clear picture.



Here is one other piece of equipment, and frankly I do not know what it is.


Thanks for your prompt response.

Jerry

 

Your a/c is not related to your boiler.

Take some pictures from far away so everyone can see how things are laid out around the boiler.

 

OK, the pics do help a lot.

Very often (TOO often for me) those pressure gauges are liars. If yours is telling the truth, your pressure is VERY low in the system. In general, the MINIMUM pressure in a boiler system would be 12-15 PSI when the boiler is cool, i.e. room temp. This pressure would increase when the system is hot, depending on some other factors, it could increase as little as a few PSI, or could go as high as maybe 25 PSI.

One thing is certain, the pressure gauge accuracy needs to be verified, and if the pressure is really only 4-5 PSI, it needs to be determined why, and corrected.

The things you are calling 'transformer valve assemblies' are your ZONE VALVES, and they appear to be Honeywell 8043 series. Since you have three zones, you should have three of these valves.

How they work:

Your thermostat is basically a switch. When it calls for heat, it switches 24VAC from the TRANSFORMER (there should be one around there somewhere, probably mounted on an electrical box) onto the terminals labeled TR and TH on the valve. You can use your multimeter to measure those and see if you are getting 24VAC on those terminals when the thermostat calls for heat. Obviously each thermostat controls one zone valve.

When the valve opens, it activates the ENDSWITCH (turns it on, closes the switch). This ENDSWITCH will then in turn activate the boiler.

The most common problem with these valves seems to be that the endswitch stops making contact, and doesn't signal the boiler or pump to operate. The valve may in fact be opening, it's just not passing the info to the boiler.

Also, the motor inside the box could be burnt out and not opening the valve, but the symptom will be the same, no boiler operation. You will still see 24VAC at the TR and TH though.

The ENDSWITCHES are all wired in parallel, so that any one of them may operate the boiler.

Turn two thermostats all the way down, and one all the way up. With your meter, check for 24VAC on TR and TH. When you find the one that's activated, label it with which zone it is.

Now turn that one all the way down, and another all the way up. Repeat above.

Turn that one all the way down, and the last one all the way up. Repeat above.

Turn the last one all the way down.

If you find that you do not have 24VAC on one of the valves, then the problem is with the thermostat or the wiring.

If you find 24VAC on ALL THREE valves, you know the problem is not with the thermostat or the transformer. If all OK so far, continue below.

Next, clip the meter on any pair of the ENDSWITCH terminals. Since these are all wired in parallel, you don't need to move the meter around for the following tests. You should see approximately 24VAC on these terminals when NO HEAT CALL is coming. When any one of the valves is open, there should be ZERO volts on the ENDSWITCH terminals.

Turn thermostat 1 all the way up. See zero volts on endswitch. Turn 1 all the way down.

Turn thermostat 2 all the way up. See zero volts on endswitch. Turn 2 all the way down.

Turn thermostat 3 all the way up. See zero volts on endswitch. Turn 3 all the way down.

If one of the thermostats does not act as above, the problem is with the endswitch (or the motor) in that zone valve, and the powerhead on the valve should be changed.

I believe you are going to find that one of the valves is not firing the boiler.

BUT... you ALSO need to know if the pressure gauge is correct or not...

See post #7 in this thread for info on how to verify the pressure gauge:

baseboard air lock

Let us know what you find and we'll continue...

 

Thanks so much for your helpful reply. I'll get started now and see what I discover.

I do have three zone valves, and one is even labeled "Living Room" and that is the zone that is not working.

I'll go down in the basement and see what I can find.

Thanks again.

Jerry
St. Peter, MN

 

Jerry, I have no idea what that Dytron box is either... is it mounted on the boiler? is it wired to the boiler control?

 

Thanks for all your help. I've turned down all the thermostats and will start reading them once things cool down a bit. Here are some more pictures and I have a question.

I thought the transformer was part of the Zone Valve. Is the transformer a separate unit? If so, then it must be working as the other two zones have heat.

Here is the boiler from the back:


Here it is from the side:


Here are two of the zone valves. Both of these are for the upstairs, and the one on the left, labeled "Living Room" is the one without heat.


Now I'll go take those multimeter readings and report back.

Thanks,

Jerry

 

Yes it is. It may be in that box to the right of the circulator, or it may be mounted anywhere around the boiler.

Here is a basic diagram of how the zone valves might be wired:



This is only showing two valves, but if there were a third, it would be wired the same way. In spite of the fact that there are no 'labels' on this drawing, it should give a good idea of what you are working with there.

 

Thanks for all of your help. I ran the multimeter and identified my three zones. The Zone Valve marked Living Room is correctly labeled. I was incorrect in thinking that the two side-by-side were for the upstairs. Actually the one on the right is for the basement. The one off by itself is for the addition to the house. Now that I think about it, that makes sense. Originally it was a two zone house with the Zone Valves next to each other. Then the addition added a new zone, and that Zone Valve was off by itself.

The furnace comes on when the LR thermostat is raised and the multimeter show 24 volts between TR and TH and zero on the Endswitch. Does that mean the valve in the Zone Valve is not working? Also, I noticed the pipe just above the Zone Valve was just warm -- not hot as it was below the Zone Valve.

If so, what is involved with the fix? It looks like the pipes have to be taken apart.

Thanks,

Jerry

 

OK, good work.

No the pipes don't have to come apart.

Since the pump and the burner are working when you turn the LR thermostat up, it means that your problem is NOT with the thermostat or the zone valve. That part is working just as it should.

To recap, you SHOULD see 24VAC on TH and TR when the thermostat is calling, and if the valve is opening and calling the boiler, the 24VAC at the endswitch SHOULD drop to zero when the valve opens.

What this means is that you have an AIR BLOCK in that zone, and it won't be long before other zones follow. This is because of the low pressure in your system.

As said earlier, 12-15 PSI is the MINIMUM pressure you should have in your system. You have 4-5 PSI. It takes 0.432 PSI to raise water in a pipe 1 foot. On top of that, you need a few extra PSI to ensure that the pressure at the TOP of the system never goes below zero. If you do the math, you will see that 4-5 PSI will get you up to maybe 11 feet above the boiler. If the boiler is in the basement, and the LR zone is more than 12 feet above, you won't have any water flow in that zone.

Additionally, the location of your circulator pump relative to the location of your expansion tank means that when the pump runs, it will SUBTRACT pressure from the system. So, even if that LR zone is less than 11 feet above the boiler, it's very possible that the pump subtracting pressure is pulling the pressure in the system below atmospheric.

Even more... there should be a device sometimes called an 'air scoop' that scours the air bubbles from the water stream and vents them from the system. You don't want air in the system because it can stop the flow. I don't see such a device in your pictures.

See post #8 in the previous reference thread for more info:

scroll to post #8

In fact, might as well read that whole thread, because the problem is very similar to yours.

more...

 

Before we do much else, the first thing that you should do is check for the proper 'air charge' on the EXPANSION TANK. That's the greenish colored tank that says EXTROL on it. On top of that tank is a valve. It's a normal tire valve. Put a tire gauge on that valve and tell us what the pressure in the tank is reading. My bet is that it will be 5 PSI or less. It should be at LEAST 12 PSI.

Normally, I would say to drop the system pressure to zero before charging the tank, but since your system pressure is already pretty low, I want you to use a small compressor or bicycle pump to add air to that tank until you have 15 PSI at that valve. We'll check it again later, after we find something else.

more...

 

Thanks so much NJ Trooper. The air pressure on the expansion tank was so low it did not register on my tire guage. I'll go to the hardware store and get a tire pump. I don't think they are open yet, so it may be an hour or so before I have any thing else to report. I'll read the thread you recommended about the five zone heat more carefully in the mean time.

Thanks so much for all of your help.

 

After you've checked the expansion tank air charge and added air to 15 PSI...

The next thing is to locate where the boiler water fill valves are located. There should be a bell-shaped thingy on a small pipe leading to the boiler from your domestic supply. That bell-shaped thing is you PRESSURE REDUCING VALVE, and is actually a regulator that drops the city pressure to the 12-15 PSI required for proper operation of the boiler.

It will look something like this, might be gold, red, green, but the basic shape is the same:


image courtesy Pexsupply.com

There should be a manual hand shut-off valve upstream of this, and there may also (if you are lucky) be one downstream. There could also be another device ahead of it called a BACKFLOW PREVENTER... but I'm not betting on that being there.

TURN OFF THE BOILER AND ALLOW IT TO COOL TO 100°F or LESS before proceeding!

Check to see if the manual shut-off valves are closed, and if they are, OPEN them and watch the pressure gauge. If they were closed, you should hear water running into the boiler and it should slow down and stop at between 12-15 PSI. Keep watching the gauge, and if the pressure continues to climb, CLOSE the manual shutoff valve again... this means they were closed because the reducing valve is leaking through.

Take pics of what you find so we can be sure we're going in the right direction.

To recap again... we're trying to get the pressure in the system up to where it should be by adding water. Also, making sure the charge in the expansion tank is correct so that the RELIEF valve doesn't open and spew water.

more...

 

Next, you need to look at the baseboards and see if you can find air bleeder valves on them... when the pressure is right, you need to go around to all of them and bleed the air out of the system. Hopefully you will have them... if you don't, we need to figure out how to get the air out.

Sounds like a lot of work, but it really isn't. Hardest part is finding and understanding how all this stuff works, and where all these components are...

Let me know how you do.

 

Adding air to the expansion tank caused the pressure gauge to jump to 15 psi. It looks like that might be working.

I did not see anything that looked line the pressure reducing valve. I'll post some pictures once I get them loaded into Photobucket.

Thanks for all of your help.

 

I thought that might happen. It's because there was water in the tank and when you added the air it pushed that water out and pressurized the system somewhat.

It's not the final solution though... you will need to do a bit more on that tank.

The air charge in the tank has to be 12-15 PSI when the other side is ZERO... so, since you did have the pressure increase in the system when you added the air, it means that you need to drop the pressure in the boiler to zero, and check the tank again. You will find that the tank now has less than 15 PSI in it again.

BUT... unless you figure out how to get water into the system, you don't want to do that yet, because you will end up in worse shape than you already are.

waiting for the pics...

 

Here is one faucet where the water enters the furnace.



There is another one above it on the same copper pipe. just above the expansion tank.



There are three drains. One is directly below the pump. The other two are below the original zone valves. I could not find a drain for the more recent zone valve for the addition. That valve is shown in the above picture between the two circled faucets. At least it has shut off valves above and below it.



I still have not been able to find a dome shaped pressure reducing valve. I thought it would have been between the two faucets on the line going into the boiler.

The good news is that we are getting heat. It heated up to a little over 70 degrees. It is pretty warm outside here, so not sure what to expect when it gets cold again.

Thanks again NJ Trooper.

Jerry

 

I believe that the Dytron is an old boiler reset control. There is a strap-on gauge in the pic of the water fill. Held with a hose clamp.

Some lightweight googling couldn't turn up any documentation. I'm guessing it's a basically a high-limit that one can adjust depending on season/condition. The flat of the knob is pointing toward about 3.5 "severe weather", so high limit is probably close to 180.

 

I thought the same thing about the Dytron... I did find a few references to the company in Waltham, MA, but they were all dated back in the 80's... and involved in 'Thermodynamics'. So, it's very possible it was a business they were in for a short time and then out again. I would trace the wiring in an attempt to figure out what it is, and whether it's still functional or not. But that's for another day...

It doesn't appear that you even have a reducing valve. Some systems don't, and rely on the manual feed. The homeowner would need to know when to add water to the system. And now you do! You would SLOWLY! open the top one a bit, not all the way, just a bit, and then SLOWLY! open the bottom one to let water in. Watch the pressure gauge as you do so, and never dump water in when the boiler is HOT. Always wait for it to cool to under 100°F.

more...

 

Things you need to know about the expansion tank:

There is a rubber membrane inside the tank that separates the water and the air. Those membranes can and do break. If during the following process, you hear what sounds like air coming out of the tank, and into the system, STOP... it might mean that your tank membrane is busted, and the tank needs replacement.

To properly charge the tank with air, shut down the boiler and allow to cool to 100... using any one of the drains (you've already got a hose on one of them, may as well use that one) open the drain and just release the pressure on the system.

Check the air charge in the tank with the tire gauge. Bump it up to 15 PSI.

Check the boiler gauge again. If it has risen from zero, open the drain and bleed off the pressure again.

Repeat the above steps until the tank holds 15 PSI and the system at zero. At this point, the tank is properly charged with air. You might want to wait a while (an hour?) with the boiler off and the pressure at zero and check the two gauges again. If you find that the system has risen, and the tank has fallen, it's another sign that the bladder membrane is defunct, and you need to change the tank.

If it holds for that time, then at this point go ahead and open the water feed valves and feed water until you have 15 PSI in the system, and close those valves again.

more...

 

Let's talk about the pressure relief valve a bit...

That is the valve on top of the boiler that shows in the pic of the black handle water feed valve.

The relief valve is a safety valve. If the pressure in your boiler rises above 30 PSI, it will open and spew very HOT! water out. (there are some cases where it would vent cold, but for safety sake, let's believe it will always be HOT! )

Heaven help anyone who might happen to be standing there when it opens... those valves are supposed to by code be piped down to within about 6" of the floor. You probably have one on your water heater... take a look at how that is done.

Boiler safety advocates recommend replacing the relief valve every FIVE years, whether needed or not. Yours is very old, and I recommend replacing it, and running the pipe down to the floor.

I know, yer sorry now that you came here, huh? Like you needed more projects, right?

 

Now that you have some pressure in your system, you have heat in that zone... but, I bet it sounds like Niagra Falls with water gushing and sloshing through the pipes, don't it?

That's because there is air in the sytem.

Have you looked at the baseboards yet to see if there are any bleeder valves on them? You can use those to let air out... and when you are done letting the air out, check the gauge on the boiler again and when it is cool, top the pressure back up to 12-15 PSI because it will drop when you let the air out.

more...

 

Then when you do that is the best time to replace the relief valve as well, because you are going to have to partially drain the boiler to do so in either case.

You won't need to drain completely though, just so the water level is below the top of the boiler to change the valve and tank.

When you drain the boiler, first CLOSE the valves on the supply and return to the baseboards. This will alleviate having to drain much water at all.

When you replace the tank, I recommend adding a few optional goodies that make life much easier in the future. See graphic below... your tank is installed opposite the pic, but the idea is the same.



This can all be easily done with black pipe nipples and a tee, so there is no soldering required.

Off the existing tee, use a short nipple, a threaded ball valve, another short nipple, and a tee. The tank will thread into the top of the tee, and the drain into the side port on the tee.

When you need to check the air, or change the tank, just hook a hose to the drain, close the ball valve (with the boiler off!) and open the drain to relieve pressure on the tank. Leave the drain open, and adjust the air, or change the tank as needed. No more fiddling around with the boiler drains... real easy.

In order to prevent accidental closing of that valve when the boiler is running, take off the handle and hang it on a nail nearby.

 

If you wanted to add one, that's where it would go.

 

Thanks again for all of your help NJ Trooper.

Surprisingly, there really is not any sound of water and air rushing in the baseboards. We unhooked three of them, but have not found the bleeder valve yet. We'll keep looking.

Here are some more pictures of the blue Dytron box.


There is 110 coming in at the top.


I'm betting these are 24 volt AC coming out the bottom. Is there any chance this could be the transformer? The red and white wires on the left go down to the boiler. The wire on the right goes up to the ceiling and possibly to the thermostats.


I did a Google search on Dytron Waltham MA and this thread was number 1. Below it was a listing on a surplus site for something that might have been a transformer for a telephone made by them.

Thanks again for all of your help. Dinner is calling.

 

No... there would be no adjustment on a transformer.

It may even go outside to a temperature sensor!

In the one pic that Xiphias commented on, that shows a temp sensor with gray wires hose clamped to the pipe... where do those wires go?

Pop the cover off, let's see what's inside!

 

Looks like it has something to do with the central air conditioner.


This was inside the cover.


Here is a wiring diagram. Could not really see this drawing until I took a picture of it and zoomed it up.


Thanks so much for all of your help. I have to get up at 4:15 in the morning, so this is a project that will have to wait until next weekend. Thank goodness we have heat. I could never have gotten this done without your help. Our other zone is also so much more comfortable.

Jerry
St. Peter, Minnesota

 

Now that I think about it, this probably is a temperature sensor like you mentioned. The severe weather setting makes me think that you could have it set on high efficiency most of the winter and then if there was extreme cold, you could move it over to the severe weather setting. Severe weather seems more like a cold winter night than a hot summer day. At least in Minnesota.

Edit added -- You asked where the wires go. The one set goes to the boiler, and the other set on the ceiling seems to go outside. It goes directly to the wall near the central air unit, and then it is covered with insulation.

Jerry

 

That is an OUTDOOR RESET CONTROL, as shown on the label. What that is 'supposed' to do is vary the boiler water temperature based on the outdoor (and apparently indoor) temperatures... by lowering the water temperature when super hot water is not needed, fuel is saved.

Howsomever, I'm sure that at some point it malfunctioned,and it appears that it has already been disconnected.

Notice that the black, white, blue, yellow wires from the board are not connected to anything, and just wire nutted with no connections.

So, I wouldn't pay it no more mind.

 

Thank you so much NJ Trooper. It is so nice to have heat this morning. I'm off to work now.

Replacing the pressure release valve looks pretty easy. I guess the boiler should be off with the temperature below 100. Looks like all I need is a pipe wrench and a large adjustable wrench. Do I put it back together with pipe joint compound and Teflon tape?

Is there anything that might cause me some trouble?

Can I use PVC pipe to route the escaping hot water down near the floor?

Thanks.

Jerry
St. Peter, MN

 

Yes... don't put tape or dope on the first two/three threads though, stay back from the end. If you use tape, ONE LAYER is all you need! A lot of guys these days have taken to using BOTH tape and compound. One layer of tape, then a bit of the dope on top.

Not really... it's pretty straight forward... just when you buy the valve (should be around $20 or so), get the right 'sex'. They are available in all three sexes...

I personally wouldn't, but I've seen it done. CPVC might be a better choice? (higher temp I think?) I don't know what the 'codes' say about plastic... Don't use black 'iron' pipe though, as tempting as it might be because it's threaded. It can rust up and clog the pipe... you don't want that.

 

I just looked at a chart that showed CPVC is acceptable...

The chart also shows that GALVANIZED steel is OK, but there are to be no threads on the bottom of the pipe, so if you use a long nipple, cut the threads off the bottom. We don't want someone tempted to put a CAP on the end of the pipe!

YOUR LOCAL CODES MAY VARY!

 

Thank you so much NJ Trooper. We still have heat, and the correct pressure in the boiler. I'll try to install the release valve this weekend and hopefully find the bleeder valves. This has been a busy week for me.

I was surprised that this thread came out number one on Google when I searched for Zone Heat Problem. Now I have an easy way to get to this site.

Hope you have a Happy Thanksgiving.

 

If everything seems to be working OK, I think I would opt in favor of waiting until spring to tackle that relief valve replacement...

Why? If you don't have a decent way to remove the air from the system, when you drain that boiler to do that job, you will be faced with lots of air in the system, and no way to get it out... then you might not have heat again.

No reason you can't run the pipes off the old one though, if you are looking for something to do.

Otherwise, have a Happy Thanksgiving! and watch a ball game or three!

 

Thanks NJTrooper and others for all of your help.

The system is working better, but the baseboards seems to becoming less effective in our cold zone. Our temperature in the cold zone is about 8 degrees lower than the thermostat setting. I suspect there still is air in the system.

I tried to purge and balance the system by doing the following, please let me know if I missed something:

1. Turned off the boiler and let the temperature drop to below 100.

2. Closed the valves (faucets) for the two zones that have heat while leaving the faucet valve open on the air blocked zone. (I am not sure if this accomplished what I wanted. If the zone valve itself was closed, then I would not be able to purge the system. I think some zone valves have a way to manually open them, but ours does not.)

3. Drained water out of the system for about 20 minutes while filling with fresh water. The water coming out of the drain hose had a good flow, and was cold when I stopped running it into the boiler.

4. Closed the drain and water inlet valves

5. Added air to the pressure tank so it was 15 pounds and drained the boiler so the pressure gauge reads zero.

6. Let it sit for an hour, and 15 pounds remained in the pressure tank while the gauge showed 0 pounds.

7. Added water to the boiler so the pressure gauge displayed 15 pounds.

8. Turned on the furnace.

I noticed the temperatures on the pipes above and below the cold zone's zone valve were both hot after this procedure. We also got some heat in the cold zone, but not as much as in the other two zones.

I have only found one bleeder valve for all of the baseboards in the cold zone. I was going to bleed it, but it has been covered over with putty. Before bleeding it, I wanted to ask if there is a logical reason why it would have been covered over? Is there any reason that I should not go ahead and bleed it?

Also, is it possible that I could just add one of those air purging devices somewhere on my current system? Perhaps on the pressure tank?

Thanks for all of your help.

Jerry

 

Take a picture... let's see...

Sure they do! On the end panel of the valve, the one with the terminal strip on it, below those terminals is a little lever sticking out of a slot. To the left it says AUTO to the right it says MAN, and then below that OPEN. You took a very nice close up pic of that earlier! Push the handle over to the MAN position and lock it into the 'notch' above it.

I'm not sure you purged the zone either... in fact, if you didn't manually open the zone valve, I'm sure you didn't.

Questions:

It appears that the zone valves are on the hot supply side of the boiler, and on the return side of the boiler, you have drains (faucets) above 'ball valves' (one of your pics shows this, and the ball valves have red and green handles.)

Is this correct?

If so, what you need to do is connect the hose to the drain on the zone you wish to purge, and CLOSE the ball valve below it.

Then, manually lock open the zone valve on the zone and open the drain.

Then, open the water fill.

By doing this, and closing the valve below the drain, you are forcing the water to take the path through the boiler, up the supply, through the manual opened zone valve, through the baseboards, back down the return and out the drain, rather than the easy route through the boiler up the return past the circ, and out the drain... water is going to take the shortest easiest path of least resistance, just like electicity. So in order to get it to go where you want it, you need to put some resistance where you don't want it to go... that's what closing the ball valve is all about.

Anything is possible. All depends on how much work you want to do!

 

Thank you NJ Trooper. It is always a good idea to ask me to take a picture. I got some more light on the bleeder valve and blew up the image. The "putty" was just dust and dirt, which I cleaned out.

We did not have a bleeder key, and the one I bought (with a new valve) does not fit into the existing bleeder valve. The existing bleeder valve is at the top, the new key is at the bottom, and the new (unattached) bleeder valve is in the middle.



Here is a picture of the zone valve with a ball valve (circled) above it. There is no ball valve below it, at least not on the same pipe. The circled ball valve is just above the cold zone valve. I left the circled ball valve open and closed the other two ball valves just above their respective zone valves.



Here is a picture of the drains. I moved the hose over to the blue faucet and used this faucet to drain the boiler while adding water. I think this is the drain for the cold zone, but I am not sure.



Right now, the cold zone is actually a comfortable 68 degrees. The thermostat is set a bit over 70. The purging last night actually did help. I am puzzled that it took 24 hours to get this zone up to a comfortable level. I also suspect that all the water I flushed through the system last night will release bubbles and cause another airlock.

Thanks for pointing out the way to manually open the drain valves. I had not even noticed them on the pictures.

Right now the temperature is quite comfortable. I am tempted to just leave things as they are and see what happens. Below zero temperatures are expected in the next couple of days. Should I try and find a key that would fit the bleeder valve?

Thanks,

Jerry
St. Peter, MN

 

You can leave the ball valves above the ZONE VALVES alone.

The ball valve I want you to close are these:



This combination of a drain with a shutoff below it is known as a "Purge Station". If you don't close the lower valve, the water you feed in will just go through the boiler and UP from the boiler, through the circulator, and out the drain valve.

By closing that ball valve, and opening the respective ELECTRIC ZONE VALVE, you will force the water up and through the zone, and out the drain.

If you can't find a key to fit, then you will have to replace. If you close the ball valves to and from that zone, and open the drain on that zone to relieve the pressure (you don't have to drain it, just relieve the pressure), you should be able to change that bleeder without draining the system. Put some old towels around, just in case!, but if you have no pressure in the zone, and it is ABOVE the boiler, you should not get any (much) leakage.