Another Boiler Running When Not Calling For Heat


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Old 12-23-13, 08:59 AM
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Another Boiler Running When Not Calling For Heat

Hi,

I have a Weil-McLain HE-5 natural gas boiler with baseboard heating. The boiler seems to always want to try to maintain a water temp of between 150 and 170 degrees, even when the thermostats are not calling for heat, the circulator pumps are not running and no heat is getting to the baseboards. As long as there's power to the boiler it will try to maintain that temperature range.

The system has two zones, two circulator pumps, and no zone valves. Both thermostats are digital and the boiler will continue to run even if both thermostats are set to "off". This unit is only used for heating, not to supply hot water for cooking, bathing, etc.

I saw in another thread that someone else has a similar issue. Based on what I read there, I believe I have a White-Rodgers aquastat (model 89140?). Inside the aquastat box there's just a single geared dial that looks like it's set to around 180. The two wires leading into this box appear to be 120 volt power lines.

My guess is that I'm dealing with some incorrect wiring/switching, but I'm looking for more insight and some guidance as to where to look to make corrections.

Thanks,

David
 
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Old 12-23-13, 09:56 AM
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How long have you had this situation? Has it ever worked properly? If so, has anything changed since it last worked properly?

Dollars to donuts, Trooper is going to ask for photos, so you might as well start shooting! Take some closeups of the aquastat with the cover off, so the experts can see how it's wired up.
 
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Old 12-23-13, 10:02 AM
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I moved in a few months ago. Didn't really notice until it got warm this weekend and the boiler kept running.
Camera is ready, I'll wait to see what trooper asks for.
 
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Old 12-23-13, 10:03 AM
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Pictures are always helpful...

How are the pumps being controlled? I presume that there must be pump relay(s). Get the model number of those relays too.

Do you own and know how to use a multimeter?
 
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Old 12-23-13, 10:29 AM
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Hi Trooper,

I've attached some pictures. One is of the aquastat (cover off), the others are of what I believe to be the pump relays (also with covers off). The relays are both Honeywell model #RA832A.
I do have a multimeter, now if only I can find it...

David
 
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Old 12-23-13, 11:59 AM
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There's probably at least one other control inside the cover of the boiler I think...

If this is wired as I suspect, the " X X " terminals of the two 832 relays should be wired in parallel and should go inside the boiler to what I suspect you will find is an R8285 control. There will be a transformer and a plug in relay on that control.

When you find your multimeter, set to measure 24 VAC range and WITH NO THERMOSTAT CALLING, measure across the X X terminals. You should see 24 VAC there at that point.

When EITHER thermostat calls for heat, you should see ZERO volts on the X X .
 
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Old 12-23-13, 12:37 PM
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There looks to be a thermostat cable running between the "X X" terminals of the two 832 relays. From one of those sets of "X X" terminals there's another thermostat cable running into the boiler and connecting to a transformer with a bunch of plug-in connections on it. Not sure if this is the R8285 control you mentioned, but it looks like it's in the right place. The thermostat wires coming from the 832 relays are connecting to plug-ins "Y" and "G" on the transformer. Would these correspond to the "X X" terminals you're asking me to test?
Attached picture shows the plug-ins on the transformer with the thermostat lines in the forefront.
Still tearing apart the basement trying to find my multimeter..
 
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Old 12-23-13, 12:53 PM
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Not sure if this is the R8285 control you mentioned, but it looks like it's in the right place.
Yes, that's it.

Would these correspond to the "X X" terminals you're asking me to test?
Yes, sounds like it.

This test will tell us which 'direction' to troubleshoot... if the problem is in the boiler, or upstream, in the relays (or the external wiring) and such...
 
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Old 12-23-13, 12:57 PM
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The thermostat wires coming from the 832 relays are connecting to plug-ins "Y" and "G" on the transformer
Please check that again... as I recall the thermostat wires (or the wires from the X X terminals in the relay) should go the R and G terminals.

Don't let any wire colors that are on the terminals trick you... the terminal labels should be visible next to the terminals.

Are the wires to the X X the two that are coming off and down toward the left?

Where does that larger red wire go?
 

Last edited by NJT; 12-23-13 at 01:30 PM.
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Old 12-23-13, 02:39 PM
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The wires coming from the "X X" terminals are definitely connecting to the pins labelled "Y" and "G". And yes, those are the wires you see coming off and down to the left. The red wire is going up to what looks like some kind of solenoid. The attached picture shows that a little better.

I tested with the multimeter (had to run out and get another one). I got a reading of 26 when not calling for heat, and 0 when calling for heat.
 
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Old 12-23-13, 03:03 PM
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definitely connecting to the pins labelled "Y" and "G"
I need to see a wiring diagram for your boiler. Is there one on the inside of the cover by chance? W-M isn't making it easy to get wiring diagrams for all the 'legacy' models. If there is one in there and you can get a clear and readable photo of it, please post.

How about a clear photo of the 'data plate' on the boiler...

Never mind... found what I need... see later messages.

The red wire is going up to what looks like some kind of solenoid
That's a 'pressure switch' that 'proves' the draft inducer blower is running before allowing the boiler to fire.

I tested with the multimeter (had to run out and get another one). I got a reading of 26 when not calling for heat, and 0 when calling for heat.
That's telling me nothing wrong upstream.
 

Last edited by NJT; 12-23-13 at 04:09 PM.
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Old 12-23-13, 03:05 PM
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Curiosity, the second pic of the relay next to the red burner switch there are 3 t-stat wires going to that relay. There should be one from the t-stat and one going to the burner. What's the third one for.
 
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Old 12-23-13, 03:07 PM
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I realize that your particular control may be a different manufacture, but they are USUALLY pin for pin compatible, meaning they are in the same relative locations. Even if the terminals are physically in different locations, the LABELING is usually the same... so something weird that I need to figure out before we go much further.

You can see by looking at the Honeywell one why I suspected differently...


image courtesy honeywell.com

Can you tell me on your control which pins are which?

For example, upper left is ____

lower left is _____

etc?


Never mind... found it.
 

Last edited by NJT; 12-23-13 at 04:10 PM.
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Old 12-23-13, 03:10 PM
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What's the third one for.
I believe that's the one that jumps down to the X X on the other relay?

It appears that the two on the bottom in the pic are going to the X X and the one on the top is on the T T ?
 
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Old 12-23-13, 03:20 PM
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Never mind... I found a 'control supplement' that is probably close enough for gummint work.

I see the differences in the terminal layout.

Standby, studying...
 
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Old 12-23-13, 03:43 PM
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I've added some wire color notations to the diagram I found.

 
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Old 12-23-13, 03:55 PM
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So now, some more questions:

When there is NO CALL FOR HEAT, and you say the boiler RUNS.

You are saying that it appears to be running NORMALLY... that is, the internal blower fan starts, the burners ignite, the boiler heats up, then shuts down for a period of time?

If so, grab that shiny new multimeter again.

Turn the boiler OFF.

Carefully remove the RED wire from the pressure switch from the "R" terminal on the transformer control.

Set your meter for OHMS (resistance) and measure between the "R" and the "Y" terminals. This should be 'infinite', 'open', 'no reading'.

What do you get? ZERO? CONTINUITY?

Carefully replace the RED wire on the "R" terminal.
 
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Old 12-23-13, 04:13 PM
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With the power to the boiler back ON, and NO HEAT CALL,

Measure from terminal "C" to terminal "G" and report voltage there.
 
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Old 12-23-13, 04:17 PM
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This his transformer I believe.


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Old 12-23-13, 04:19 PM
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OR, just go and get a new plug in relay for about $20 or so... and try that.

The only way this can be doing this is if the relay is CLOSED when it should not be.

Let me find you some relays that will work...
 

Last edited by NJT; 12-30-13 at 03:10 PM.
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Old 12-23-13, 04:20 PM
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This his transformer I believe.
Yep, found it, thanks!......................
 
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Old 12-23-13, 04:26 PM
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Im sorry he has the fenwal


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Old 12-23-13, 04:31 PM
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.................................................
 
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Old 12-23-13, 04:40 PM
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On Amazon, more than double the price you should pay:

R8222U1006 - Amazon.com

At Patriot Supply, correct price, 1-2 weeks delivery:

DISCONTINUED. REPLACED BY R8222U1079

Patriot Supply - R8222U1079

At Pex Supply, IN STOCK, FAST TRACK SHIPPING:

R8222U1079 - Honeywell R8222U1079 - 24 V General Purpose Relay with DPST N.O. switching

You should also be able to find a replacement for this locally if you have a well stocked supply house nearby. They should be able to cross the Honeywell part number to several other manufacturer replacements... bring the number with you.
 
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Old 12-23-13, 04:41 PM
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Mike, I already posted the ladder diagram with the Fenwal...

No, can't be the module. It is not even powered until CR2 'makes'.
 

Last edited by NJT; 12-23-13 at 05:42 PM.
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Old 12-23-13, 04:59 PM
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Resistance reading across "R" and "Y": No change in reading on multimeter. Display shows 1 before, during and after reading. BTW, crossing the tester tips gives a reading of 00.0.

After re-installing red wire and turning boiler power back on, voltage reading across "C" and "G": 00.0
 
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Old 12-23-13, 05:36 PM
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When there is NO CALL FOR HEAT, and you say the boiler RUNS.

You are saying that it appears to be running NORMALLY... that is, the internal blower fan starts, the burners ignite, the boiler heats up, then shuts down for a period of time?
And then repeats the whole process? over and over?

This is what happens? including the blower running?
 
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Old 12-23-13, 05:41 PM
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You need to be VERY CAREFUL! for the following step, you will be measuring 120 VAC! Do NOT accidentally short the probes together! Do NOT touch the terminals with your fingers!

Set the meter to read the 120VAC range... (unless it's auto-ranging)

Measure from L1 to L2 on the Fenwal module with NO CALL FOR HEAT.

What do you get there?
 
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Old 12-23-13, 05:45 PM
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When there is NO CALL FOR HEAT, and you say the boiler RUNS.

You are saying that it appears to be running NORMALLY... that is, the internal blower fan starts, the burners ignite, the boiler heats up, then shuts down for a period of time?
And then repeats the whole process? over and over?

This is what happens? including the blower running?
Yes. That's what it does.
 
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Old 12-23-13, 06:10 PM
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I'm thinking that you are off measuring L1 and L2 ... I'm holding off waiting until an answer on that before forging ahead.....................................
 
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Old 12-23-13, 06:34 PM
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Something odd about that Fenwal module.

It does NOT resemble the 05-21 (which is what the schematic says that it is) that I have found on their website.

I'm wondering is someone retro-fitted a different model and screwed up the wiring...

Please give me all the part numbers off that module.
 
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Old 12-23-13, 06:47 PM
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Measure from L1 to L2 on the Fenwal module with NO CALL FOR HEAT.

What do you get there?
I can't find bare metal to make contact with the probes on either L1 or L2.
 
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Old 12-23-13, 06:51 PM
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The Fenwal model is 05-32
 
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Old 12-23-13, 06:59 PM
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Dave,
Turn the boiler off and either pull the connectors up enough to put your probes on or remove the connectors and put your probes into the connectors to see if you have juice.
 
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Old 12-23-13, 07:15 PM
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The Fenwal model is 05-32
Going to look at that one right now.

I'm going to ask you to trace some wires...

If you can't get the probes on L1 and L2, we'll find some other way if Spott's idea doesn't work.
 
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Old 12-23-13, 07:22 PM
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Troop yes you may be right about the fenwal but I have seen this happen before...

But I dont remember... I stated the module but you said it cant be...( I remember module causing issues and why I stated it... )

Your the wire man though... My advice is from memory in the field with the HE's

But anyway look at the pics and the old screw holes where the fenwal is... You may be right it was changed.

Just saying...

 
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Old 12-23-13, 07:26 PM
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No luck, not on the website.

Can you get a close up of that so I can see the labels and the terminals please?
 
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Old 12-23-13, 07:30 PM
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I stated the module but you said it cant be
If the wiring is not all caddy-wompus, it can't be... look at the wire diagram. Both the 120VAC that powers it and the 24VAC that signals it to operate should not be there. No power to control, no operate. But it DOES operate.

right it was changed.
And I bet that they screwed the pooch on the retrofit.

I just bet that they've got the 120 hardwired to it directly and for all we know, they 24VAC also...

It wouldn't surprise me if the pressure switch is also 'out of the loop'...
 
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Old 12-23-13, 08:37 PM
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Dave,

Here's an updated diagram. I've changed the terminal designations a bit to match what I believe is on the 05-32. Also added a bunch of info that may help you troubleshoot.

Carefully examine your system and see if you can use this to figure out what's going on there.



This is the way the control replacement SHOULD HAVE BEEN DONE. I strongly suspect that you are going to find that there is a CONSTANT 120VAC wired to L1 and L2, and also suspect that you will find the same thing with a CONSTANT 24VAC between "TH" and "GND" on the replacement control.
 

Last edited by NJT; 12-23-13 at 09:27 PM.
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Old 12-24-13, 06:37 AM
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An update:

Last night when I was performing the tests you recommended, the system was actually working properly, only running when the thermostat was calling for heat.

However, I had turned the system off for two days due to warm weather and the boiler was cold. During each test, I never allowed the system to run long enough to fully heat up the water, only long enough to get a test result. Since it seemed to be working correctly, I was beginning to think I had imagined the whole problem.

Before going to bed, I turned the system on, knowing that it was supposed to get cold again. During the night, the boiler kicked on to supply heat. As of this morning, the system is once again trying to maintain a high water temperature (without running the circulators), even after the thermostats are both turned down and set to "off". In fact, I turned the thermostats off about an hour ago, yet as I type this, the boiler just kicked on once again. At this point the only way to stop it would be to power down the system.

Do you think I'm dealing with an intermittent problem, or is it possible that one of the controls (Fenwal?) is trying to maintain the high water temperature once a given temperature threshold is reached?

BTW, thanks so much your help.

David
 
 

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