Boilers - Steam and Hot Water Systems - Valve Problem?!

HI,

I purchased a home built in 1899 recently. I live in Colorado and it is starting to get cold! I have a hydronic boiler that is about 30-40 years old. I have 5 zones with Taco 555-050 heads. Some green and some the newer brown. Last week my master bedroom zone just kept running hot and the thermostat no longer controlled the zone. So I went downstairs and disconnected the three wires, red on the #3 wire, white on #2, and the #1 wire is the thermostat. The heat still remained on. So I ordered a new zone head and replaced it last night. This is where my confusion comes in.

I have a temperature control placed on the boiler so it has to be 60+ degrees to run. Yesterday it was in the 70s (snowing today!) so the boiler was off. First I connected the red to the #3 wire. As soon as the white wire touched the #2 terminal the motor kicked on and I could hear water flowing (even thought he entire unit should have been off). I then connected the #1 wire which is the thermostat. I am pretty sure I have a problem because the thermostat int calling for heat yet the manual lever is loose and it easily moves between on and auto.

Any ideas what is going on?! I had a plumber out last week who told me to replace the head and he charged me $70 just to show up. I have no problem with people making a living, but I cannot afford to call him back again to diagnose the new issue. Thank you all so much!

Chris

disconnected the three wires, red on the #3 wire, white on #2, and the #1 wire is the thermostat. The heat still remained on.

You DISCONNECTED the wires, and the heat kept running?

Then how could this valve be at fault? If it was this valve at fault, shouldn't the boiler have shut down when you disconnected it?

First I connected the red to the #3 wire. As soon as the white wire touched the #2 terminal the motor kicked on and I could hear water flowing

You should have had the boiler turned off when you did this. Even though it's low voltage wiring, it's not good practice to wire things up with the power turned on.

Here's what I think are some of the possibilities:

1.You made the assumption that your boiler control had shut the system down due to warm weather, when in fact it had not. If the system was truly in WWSD (Warm Weather Shut Down), it would not have fired up under any circumstance.

2. The NEW valve is defective, if without any power connected to it, it was in the open position.

3. The reason that the BR zone keeps getting heat is because that valve is stuck OPEN, but NOT the one that is calling the boiler for heat. In other words, ANOTHER zone was ALSO calling for heat, and with the BR zone valve stuck OPEN, it was ALSO getting the heat.

Thank you so much for the response. Yes, when I disconnected the wiring (thank you for the advice on shutting off the power in the future) the heat stayed on. The heat did turn off when I removed the power head from the valve. My thoughts were that the head was malfunctioned in the on position? So with no power head on the valve the heat was off. WHen I placed the new head on the motor has not stopped running even though the temperature in the MB has been reached. Are these possibilities accurate:

1. New head is broken as well as the old one (what are the odds of this?)

2. Some sort of short in the wiring?

What does it mean if the temperature in the room has been reached, or I turn off the heat all together in the MB, and the Taco unit control arm still moves up and down with the tension it should have?

Again, thank you so much for assisting someone who unfortunately needs to DIY.

Quick update. So today is when I wired the new valve head. As I said when I wired the #2 and 3 wires the motor started running. I just came upstairs and realized I had left the thermostat in the off position (I have also tested different thermostats to make sure it wasnt them). Even though the thermostat is "off" the heat is on in my MB. So with the valve head installed I get constant heat and constant motor, without the valve head installed on the valve the heat is off. What can be causing this and how do I test it without buying another valve motor? Thanks guys!

Chris, I think I'm all confused!

I'd like to define some terms so we all understand.

When you say that 'the heat stays on', I believe that you mean that the room keeps receiving heat, and NOT NECESSARILY that the BOILER IS FIRING, or that the CIRCULATOR PUMP is running. Is that correct?

If a valve is defective, and is MECHANICALLY staying open, that zone will get heat whenever ANOTHER zone calls for it.

When you say 'the MOTOR is running', I presume that you mean the CIRCULATOR PUMP MOTOR, is that correct?

If the heat stops flowing into the MBR when you remove the powerhead, OLD or NEW, there are a couple possibilities. It could be that the OLD head is defective, and the new head is ALSO defective, OR... it is being installed improperly, and somehow holding the valve open.

Is it possible that you have somehow mixed up the wiring when you installed the new powerhead?

Terminal 3 on ALL the valves should be strung together, and should ONLY go to the aquastat on the boiler.

Terminal 2 on ALL the valves should be strung together, and should go to one side of the transformer, and ALSO to the other terminal on the aquastat on the boiler.

Terminal 1 on EACH valve should go to one of the terminals on EACH thermostat.

The OTHER wire of the transformer should go to the OTHER terminal on ALL the thermostats.

I don't know if pictures will help, they often don't when there are wiring questions, but I will look at them and it may help.
FREE account / Image hosting, free photo sharing & video sharing at Photobucket (http://www.photobucket.com) / upload pics there / place a link to your album here ...

Sorry for the confusion but I am new to boilers!

Correct the room baseboard heater remains hot 100% of the time, no matter what the thermostat is calling for

Yes, the circulator pump. I can hear it running in my basement right now, and it hasnt turned off since I wired the new power head.

I am sure the wires are correct as I labeled them, and they are colored the same on every head. I will double check them tomorrow.

This all started about a week ago. I came home one night and my room was 78 when the t-stat was set at 65. So I took off the powerhead and the heat off, but two days later, with the power head still off it came back on? I am very confused on what it could be, and the most furstrating thing is I have no idea how to test it to narrow down the issues. I may take the power head off again tomorrow to see if the heat stops.

Why would the circulator pump keep running? Thats what makes me think something else is going on? Could there be somekind of short?

Thank you for the help! By the way my thermocouple failed yesterday and I was able to replace it. When it rains it poors!

Perhaps a bit of explanation as to how the system should work, based on what little I know of your system... still, the principles are the same...

On the boiler: There are controls that fire the burner, and turn on the circulator. Newer boilers have a single control, which combines the functions of several controls. Your boiler may be old enough to have several.

There is the AQUASTAT element which sets a HIGH limit for the water temperature. When the water gets hot enough, it will turn the burners off.

There is a circulator relay which turns the circulator on/off in response to a heat demand.

If there is a heat demand (signal from home that it needs heat, comes from either a single thermostat, OR one or more zone valves) the circulator will always run, but the burner may cycle on and off based on the water temp in the boiler.

When the heat demand is ended, both the burner and the circulator should turn off.

more...

ZONE valves:

Individual zone thermostats are connected to the zone valves. When any one of the thermostats calls for heat, it will open the valve for water to flow into that zone.

Inside the zone valve, there is what is called an 'ENDSWITCH'. This switch is operated by the valve when the valve opens, and this switch is wired to the boiler controls to tell the boiler when a valve is open, and needs heated water.

The individual thermostats do not communicate directly with the boiler. They only tell the valve to open. It is the VALVE that tells the boiler to turn on.

It's like the thermostats says to the valve: "Pssst, I'm cold! give me heat!, and pass it on!"... so the valve says to the boiler, "Hey! wake up! I'm open cuz the thermostat is cold!"

more...

I know that last paragraph was kinda silly, but it is Friday... Beer 4U2

So, you can see that any ONE, or more, valves can call the boiler to turn on. Those endswitches are all wired in parallel...

Now, if a zone valve is PHYSICALLY stuck open... not because it's being told to open by it's thermostat, but actually STUCK open, it will allow hot water to flow to that zone when ANY ONE OR MORE of the OTHER valves open.

I'm getting 'mixed' diagnosis on this thread... sometimes it sounds as though you are talking about a stuck open valve, and a zone overheating when another zone is calling for heat; and sometimes it sounds as though the valve you are working on is causing the boiler to try to constantly heat.

I would really like to see pictures... if you have a camera, it's really not that difficult to upload to photobucket.

more...

OK, with all that said, here's what I'd like you to do... DISCONNECT the MBR zone valve, and tape up the wires so they can't touch anything, or each other.

Turn ALL the other thermostats all the way down.

Go to each thermostat, one at a time, and turn it up until it calls for heat. Observe how the boiler reacts.

Each thermostat should be able to control the boiler. The circulator motor should run when you turn it up, and if the boiler is cool enough, the burners may fire. When you turn it back down, the burners (if firing) and the circulator should stop.

If you see anything different, tell us what is happening.

The reason we're doing this is to determine if you have more than one problem that is confusing the diagnosis.

If all seems well, we'll go back to diagnosing the problem with the MBR zone.

Okay I will do that. Can I manually open each valve one at a time instead of going to the thermostat?

I am thinking I have a stuck zone valve. I pulled the power head off last week and the heat in our room turns on and off. I assume it is one whenever another zone is calling for heat, and off when they are not? I will still do the test to make sure.

If it is a stuck zone valve what is the labor time to drain the system, replace the valve, and remove all of the air? Money is tight for my family as I am sure it is with many families right now. Thank you!

I'd rather have you work them with the thermostats, just to be sure that there isn't some other problem. In effect, excercise EVERYTHING else to be sure that it is all working properly.

So you are thinking that the VALVE BODY ITSELF is stuck open, because without the power head installed, you get heat into that zone when another zone calls for heat, even with the powerhead on the 'questionable' valve removed?

I'm not sure, but I think on the Taco valves that they open when you remove the head? Anyone know? TO ? Grady ? Buehler ?

What bugs me is that early on, you said that as soon as you connected the wires to the NEW head, that the system started...

The valves are closed with the power head off.

With the wires off of THAT valve is the manual lever easy or hard to open?

If easy replace the valve. If hard there is a short some where.

Thanks for the response. I believe the valve easily opens when completely disconnected from the system.

NJ Trooper: I will test it starting tonight. I am just guessing the valve is stuck open because without the power head connected I am still getting heat and that shouldnt happen correct? My room was 73 this morning and I am sure my bill is going to be HUGE!

Yes when I connected the #3 and #2 wires the circulating pump came on immediately. Would that happen if the valve was stuck open, or do I have multiple issues?

Thank you so much!


The valves are closed with the power head off.

With the wires off of THAT valve is the manual lever easy or hard to open?

If easy replace the valve. If hard there is a short some where.

I wanted to check in and thank you all for your help. I ended up giving in and hiring a company as I couldnt figure it out and didnt have time to with our room almost 80 degrees. I ended up being a rusted open valve that wouldnt close. They cut it out and replaced it.

I do have a follow up question though. The 30PSI pressure relief valve on the boiler is popped and I cannot get it reset. What does this mean? HOw do I get it reset? The pressure is hovering right around 28 at the moment. Thanks again everyone!

What do you mean "popped"? It's open and spewing water? If it is stuck open, you needs to be replaced.

Your pressure should be something like 12-15 psi while cold. 28 psi is way too high, there is something else wrong with your system if it is that high.