Thermopride OL-16 Terminals


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Old 02-22-08, 05:15 PM
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Question Thermopride OL-16 Terminals

I have a Thermopride OL-16 that I'm trying to get a humidifier to work with. The humidifier needs 24v power from a switched source in the furnace (either heat-call(W) or fan(G)). Inside the furnace I have all the standard terminals (W, G, Y, C, R). The only one that shows 24v to Common is the R terminal, and that's constant even when the heat is off. The rest show no voltage at all at any time. My furnace seems to be working just fine in all modes, so I'm wondering why I can't get 24v switched power at the junction box transformer. Is it normal on this model to not have 24v on the W or G terminal?

Thanks.
 
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Old 02-22-08, 05:46 PM
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Wink

Your best bet is to get a sail switch . With this any time the blower turns on it will turn on the humidifier for you.

Or Get a A50 relay this goes around a leg of the blower anytime that the blower turns on then it will turn the humidifier. Both have to feed to a humidistat to control the humidifier.
If you have a meter you should get 24V from R to C

The R to G is fan R to W is heat R to Y is cool
 
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Old 02-22-08, 07:43 PM
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This very new Aprilaire unit is constantly powered by a separate 24v transformer, so the only thing that needs to get powered on and off is the water valve circuit. I actually had an A50 relay in line with the W/G circuit, but for some reason (on 2 different A50s) the relay never opened even when far away from any current The manual says to put the A50 inline with the water valve circuit, so I guess that's an option (assuming I can get a relay that actually opens and closes ).

These are my readings:
R to C = 30v
R to G = 30v
R to W = 16v
R to Y = 0 (I'm not in AC mode now)
I get these readings regardless of whether there is a fan or heat call.

Does this suggest something is wrong with my system transformer that these terminals hang off of?

The humidifier manual says to connect it's W/G and Cf terminals to W and C on the furnace to operate during a heat call. Is that not correct for this type of furnace, and should I use W and R instead? I'm not anxious to damage the furnace or the humidistat.

Thanks again.
 
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Old 02-23-08, 05:54 AM
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FYI, I reposted in Humidifier forum in case that's a better place to gather this info.
 
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Old 02-23-08, 01:03 PM
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Humidifier

You can break the water valve circuit using the A50 clamped around the heating speed blower wire. OR You could break the whole 24 volt humidifier circuit. This is how I normally do it.
 
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Old 02-23-08, 01:08 PM
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Initially we tried to break the 24v circuit with the A50 and 2 different A50s didn't work at all (remained closed even with no current). I guess I'll have to spring for yet another A50 and try this again (but I have to say I'm not encouraged ).
 
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Old 02-23-08, 01:12 PM
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Then why dont you try a sail switch. They work good for what you want to do.
 
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Old 02-23-08, 02:05 PM
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Sail Switch

If you have A/C the humidifier would be energized in cooling as well if you use a sail switch.

When installing the A50 read the instructions carefully. Failure to follow them will result in damage to the relay.
 
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Old 02-23-08, 02:17 PM
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Originally Posted by Grady View Post
If you have A/C the humidifier would be energized in cooling as well if you use a sail switch.

When installing the A50 read the instructions carefully. Failure to follow them will result in damage to the relay.
I have the instructions from the new one we used (that also didn't work), so I will look at them again. I think we had it hooked up correctly, trying to break the R/C circuit from the humidifier. Regardless, these new HUMs from aprilaire say to break the H/H line, which is what I'll try this time. I won't have an opportunity to do this until next weekend, but will report back when I do. I'm not familiar with a sail switch.

I'm still curious if anyone has any idea why the terminals on the transformer in my furnace don't have the right voltage. I have had problems with the electrical hookup with this thing before, and I have a feeling my contractor (I have a yearly maintenance contract -- and good thing ) took a shortcut to keep from having to replace something that's really broken?
 
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Old 02-23-08, 02:36 PM
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Voltage

It's not unusual to see 28+ volts with no load. Your meter is set for AC volts is it not?
 
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Old 02-23-08, 02:43 PM
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If you use a sail switch there . You just turn the humidistat down when you go over to AC.
 
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Old 02-23-08, 04:59 PM
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Originally Posted by Grady View Post
It's not unusual to see 28+ volts with no load. Your meter is set for AC volts is it not?
Yes, AC volts. The only terminal with any voltage is R, and it shows voltage drop to every other terminal. Everything else across to C shows 0. I can only assume that G, W, Y, and C are all at 0. (And this is with the system on a heat call and not). During my next maintenance visit from my furnace contractor, I'm going to question them on why these terminals are not energized. And maybe insist on some additional repairs.

Originally Posted by Ed Imeduc
If you use a sail switch there . You just turn the humidistat down when you go over to AC.
That may be what my contractor initially suggested (when he couldn't get the A50s to work). Aprilaire did not like this option either, and I'm not inclined to cut any holes in the duct work myself. It's worth another $35 to try another A50 and see if I can get it to work.
 
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Old 02-23-08, 05:58 PM
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Voltages

Y is just a tie point. A place to hook two wires together. It does not even need to be there. You could connect the Y wire from the stat directly to the Y wire going to the outdoor unit & it would make no difference at all, none. Your voltages are fine. You are getting all worked up over nothing.
W on the fan center should not be connected. R on the fan center should go to Rc on the stat. Rh on the stat should be connected to the primary control on the burner. W on the stat should be connected to the other terminal on the primary.
 
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Old 02-23-08, 06:10 PM
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Originally Posted by Grady View Post
Y is just a tie point. A place to hook two wires together. It does not even need to be there. You could connect the Y wire from the stat directly to the Y wire going to the outdoor unit & it would make no difference at all, none. Your voltages are fine. You are getting all worked up over nothing.
W on the fan center should not be connected. R on the fan center should go to Rc on the stat. Rh on the stat should be connected to the primary control on the burner. W on the stat should be connected to the other terminal on the primary.
Surprisingly (to me the novice), this actually makes sense . I have two wires from the t-stat going to the two burner terminals (L1 and L2) So if I jump L1/L2 to C, shouldn't I see some voltage -- I don't?
 
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Old 02-23-08, 06:18 PM
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L1 and L2 ????

I have never seen a primary control with terminals for the thermostat labeled as L1 & L2. That designation usually means line voltage. DO NOT jumper anything from the primary control mounted on the burner to C on the fan center. To do so will likely result in the frying of the primary control transformer. That furnace has TWO sources of low voltage. The primary control contains a transformer & so does the fan center. The two should never mix.
 
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Old 02-23-08, 06:58 PM
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Originally Posted by Grady View Post
I have never seen a primary control with terminals for the thermostat labeled as L1 & L2. That designation usually means line voltage. DO NOT jumper anything from the primary control mounted on the burner to C on the fan center. To do so will likely result in the frying of the primary control transformer. That furnace has TWO sources of low voltage. The primary control contains a transformer & so does the fan center. The two should never mix.
My bad. The burner has 4 terminals on it. Two look like serious gauge 110+v cables (I stay away from that). The other two have low voltage wires from the t-stat hooked up to them. All the other terminals I've been dealing with (W, G, Y, R, C) are on a transformer bolted to a 110v box on the inside of the furnace. On the outside of where that transformer is bolted on is the rest of the 110v box with 2 outlets and the cutoff toggle for the entire furnace.

Hmm, you mentioned two sources of 24v power. I only see the one transformer. Is that the fan center, or the primary?
 
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Old 02-23-08, 07:41 PM
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lol, I just posted something about this on your cross post in the other forum! The two T terminals there going to the thermostat must have a transformer under them just passing R (24v) up to RH and when the heat is on and t-stat is calling and closes the circuit passes voltage back down to the other T (just a loop) and closes a relay.

Michael
 
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Old 02-23-08, 07:48 PM
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Originally Posted by mike2501 View Post
lol, I just posted something about this on your cross post in the other forum! The two T terminals there going to the thermostat must have a transformer under them just passing R (24v) up to RH and when the heat is on and t-stat is calling and closes the circuit passes voltage back down to the other T (just a loop) and closes a relay.

Michael
That makes good sense. I just checked and I get 30v between T and T when there is no call for heat. Is there any way I can use that to trigger the HUM?
 
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Old 02-24-08, 06:13 AM
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So, sleeping on this now, if I could find a good ground on the "primary", then I could hook the HUM (R) to the T that has the W wire from the t-stat, and the C from the HUM to the ground that I find on the primary. Then I would just have to figure out how to get that ground...
 
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Old 02-24-08, 07:00 AM
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Originally Posted by Grady View Post
Y is just a tie point. A place to hook two wires together. It does not even need to be there. You could connect the Y wire from the stat directly to the Y wire going to the outdoor unit & it would make no difference at all, none. Your voltages are fine. You are getting all worked up over nothing.
W on the fan center should not be connected. R on the fan center should go to Rc on the stat. Rh on the stat should be connected to the primary control on the burner. W on the stat should be connected to the other terminal on the primary.
Grady,
As I dive into this more, I see on the wiring diagram that W from the t-stat is connected to W on the fan center relay, and then from there to T on the primary. How does that sync up with your assertion that the two shouldn't mix? Could I in fact re-wire it that way without creating any problem, and then use the W to C voltage on the fan center to drive the HUM?
 
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Old 02-24-08, 07:00 AM
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24 Volt Wiring

The primary control, the box mounted on the burner & has the red reset button, has a 24 volt transformer in it. That transformer is not heavy enough to power the humidifier. BTW, the two terminals marked F & F, are not 120 volts. The connect to the cad cell (flame sensor).

There is a second transformer incorported into the fan center, the box with the terminals marked R, C, Y, W, & G. It is not heavy enough to carry the humidifier & the other loads combined.

You need a third transformer dedicated to the humidifier. The line voltage side should be connected downstream of the furnace service switch.
 
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Old 02-24-08, 07:39 AM
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As I dive into this more, I see on the wiring diagram that W from the t-stat is connected to W on the fan center relay, and then from there to T on the primary. How does that sync up with your assertion that the two shouldn't mix? Could I in fact re-wire it that way without creating any problem, and then use the W to C voltage on the fan center to drive the HUM?
W on the fan center is functionally the same as Y. It is just a tie point.
 
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Old 02-24-08, 09:32 AM
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Originally Posted by Grady View Post
The primary control, the box mounted on the burner & has the red reset button, has a 24 volt transformer in it. That transformer is not heavy enough to power the humidifier. BTW, the two terminals marked F & F, are not 120 volts. The connect to the cad cell (flame sensor).

There is a second transformer incorported into the fan center, the box with the terminals marked R, C, Y, W, & G. It is not heavy enough to carry the humidifier & the other loads combined.

You need a third transformer dedicated to the humidifier. The line voltage side should be connected downstream of the furnace service switch.
OK. You are correct. There is a third transformer on the outside of the furnace mounted to the 110v box that actually powers the HUM (R and C). What I mean to hook up to the furnace fan controller is the W/G and Cf terminals from the HUM. They only provide the trigger for the HUM. And since I can't get a ground on the primary furnace transformer, I thought I would jump the t-stat W to W on the fan controller, and then to T on the furnace (that's what the Thermopride wiring diagram shows). Then I can use the W and C on the fan controller to trigger the HUM.
 
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Old 02-24-08, 11:06 AM
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Originally Posted by JRRF1 View Post
...I thought I would jump the t-stat W to W on the fan controller, and then to T on the furnace (that's what the Thermopride wiring diagram shows). Then I can use the W and C on the fan controller to trigger the HUM.
Well, I tried this and it still didn't work. I continued to get 0v from W to C on the fan controller, and of course the HUM wouldn't get triggered then either.

I rewired the HUM to use an A50, and as soon as I get one I'll put it in-line with the H wires on the h-stat. In the mean time, I just jumped the H wires so the HUM runs continuously, and I'm keeping the furnace fan going constantly too. I must say this whole experience has been

Next question. Is there any way for me to test that I'm getting 4+ amps down the blower wire that I'm going to loop through the A50?
 
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Old 02-24-08, 11:14 AM
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Humidifier

If the furnace is not hot, turn that humidifier off. To leave it on invites damage to the furnace & gobs of mold.

In my opinion, putting a humidifier on a furnace is one of the absolute worst things you can do to your furnace. I probably remove 20 for every one I install.

To check amp draw you will need a clamp on ammeter.
 
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Old 02-24-08, 12:39 PM
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The reason why you got nothing by wiring it to W on the fan center is because the W on the fan center is nothing but a screw going to nothing that is just used to hold a wire. The W is still pulling it's power from one T and feeding it back to the other T so you would have to have the common leg on the transformer for the T.

Of course you'd still have to get the thing apart to get to the common low voltage side of the transformer, see what the ameprage rating on the transformer was, see what the amp draw was on the transfomer (LV side) when the heat was on and then see what OHM coil is on the LV relay that turns on the humidifier so you could figure if the transformer has enough juju magic to do the job

Michael
 
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Old 02-24-08, 01:06 PM
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Originally Posted by mike2501 View Post
The reason why you got nothing by wiring it to W on the fan center is because the W on the fan center is nothing but a screw going to nothing that is just used to hold a wire. The W is still pulling it's power from one T and feeding it back to the other T so you would have to have the common leg on the transformer for the T.

Of course you'd still have to get the thing apart to get to the common low voltage side of the transformer, see what the ameprage rating on the transformer was, see what the amp draw was on the transfomer (LV side) when the heat was on and then see what OHM coil is on the LV relay that turns on the humidifier so you could figure if the transformer has enough juju magic to do the job

Michael
Michael,
You just convinced me that there is no way I'm going to be able to do that . I'll see if I can get the A50 to work.

[QUOTE=Grady]
If the furnace is not hot, turn that humidifier off. To leave it on invites damage to the furnace & gobs of mold.

In my opinion, putting a humidifier on a furnace is one of the absolute worst things you can do to your furnace. I probably remove 20 for every one I install.

To check amp draw you will need a clamp on ammeter.
[\QUOTE]

Grady,
The HUM still only runs when it calls for more humidity. It will only be on full time this week until I can get a new A50 on there.

I have to tell you, I've always had a HUM in every house I've owned. This is the first I've heard of NOT installing one. What about comfort, breathing, cracking furniture, etc.? Admittedly I also use a de-humidifier in the summer in my basement when it gets damp. But in the winter the humidity in my house is less than 25% which is VERY dry.
 
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Old 02-24-08, 01:10 PM
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Originally Posted by mike2501 View Post
The reason why you got nothing by wiring it to W on the fan center is because the W on the fan center is nothing but a screw going to nothing that is just used to hold a wire. The W is still pulling it's power from one T and feeding it back to the other T so you would have to have the common leg on the transformer for the T.

Of course you'd still have to get the thing apart to get to the common low voltage side of the transformer, see what the ameprage rating on the transformer was, see what the amp draw was on the transfomer (LV side) when the heat was on and then see what OHM coil is on the LV relay that turns on the humidifier so you could figure if the transformer has enough juju magic to do the job

Michael
Michael,
You just convinced me that there is no way I'm going to be able to do that . I'll see if I can get the A50 to work.


Originally Posted by Grady View Post
If the furnace is not hot, turn that humidifier off. To leave it on invites damage to the furnace & gobs of mold.

In my opinion, putting a humidifier on a furnace is one of the absolute worst things you can do to your furnace. I probably remove 20 for every one I install.

To check amp draw you will need a clamp on ammeter.
Grady,
The HUM still only runs when it calls for more humidity. It will only be on full time this week until I can get a new A50 on there.

I have to tell you, I've always had a HUM in every house I've owned. This is the first I've heard of NOT installing one. What about comfort, breathing, cracking furniture, etc.? Admittedly I also use a de-humidifier in the summer in my basement when it gets damp. But in the winter the humidity in my house is less than 25% which is VERY dry.
 
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Old 02-24-08, 02:28 PM
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Humidifier

I'm all for increased humidity but not via a humidifier connected to the furnace. I've seen WAY too many furnaces damaged, even destroyed, by humidifiers. In a week, you probably won't get mold growth but all that extra humidity creates an excellent environment for it.
My suggestion of not running the humidifier until you can get a relay stands.
 
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Old 02-24-08, 02:43 PM
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Right now the fan is on continuous, and the HUM is cycling on and off based on the actual humidity level. Are you suggesting that even that is no good? The HUM will not attempt to put any more moisture in the air than it's internal control calls for. That's the beauty of these newer units. Even though the HUM is constantly energized, the water valve will still shut off when the right humidity level is reached. This is also a bypass unit, so any moisture left in the pad will get blown into the ducts even when the water valve has been shut off. I don't feel this is the ideal setup, but only because I don't care to run the furnace fan continually. Is there some thing else I'm not understanding?
 
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Old 02-24-08, 02:53 PM
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Humidifier

I understand your set up exactly & still suggest shutting it down.
 
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Old 02-24-08, 03:07 PM
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Thanks. I appreciate the advice.
 
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Old 02-24-08, 05:14 PM
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I agree with Grady about humidifiers in general. What it usually tells me when a customer asks for a humidifier is that their house is leaky. Usually there is way too much house air going out through the attic and bringing in dry winter air from the outside. I suggest using the humidifier money to repair the air leakage and keep the moisture inside that is created inside. Instead of adding moisture so it can be drawn out through the attic with 30% of the energy that we pay big bucks for today. Just another bite of food for thought.

Ken
 
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Old 02-24-08, 06:11 PM
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Originally Posted by KField View Post
I agree with Grady about humidifiers in general. What it usually tells me when a customer asks for a humidifier is that their house is leaky. Usually there is way too much house air going out through the attic and bringing in dry winter air from the outside. I suggest using the humidifier money to repair the air leakage and keep the moisture inside that is created inside. Instead of adding moisture so it can be drawn out through the attic with 30% of the energy that we pay big bucks for today. Just another bite of food for thought.

Ken
No argument there. This is a 40 yo house that leaks like a sieve. There is likely little insulation left in the walls or roof (don't even have an attic). But we don't plan on being here long to get any return on that type of investment (and it would be significant in this type of house).

Conversely, I have another house that is only 10 yo. It's wrapped up and insulated tight as a drum and it still makes good use of a humidifier. After all, if it's 35 deg outside and 50% RH, then if it's 70 deg inside the RH inside is going to only be 25%. And that's too dry.
 
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Old 03-08-08, 03:01 PM
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A50

Originally Posted by JRRF1 View Post
Initially we tried to break the 24v circuit with the A50 and 2 different A50s didn't work at all (remained closed even with no current). I guess I'll have to spring for yet another A50 and try this again (but I have to say I'm not encouraged ).
Well, I got another A50, and low and behold, it works like a charm when put in the water valve circuit. Can't imagine what was wrong with the 2 A50's my contractor tried, but I'm delighted it was eventually so easy.

Thanks again to everyone for your help!
 
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Old 03-09-08, 07:23 AM
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A50

If an A50 were connected with no load, such as just checking for continuity, it will be damaged. In any case, glad you got it fixed.
 
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Old 03-09-08, 10:36 AM
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Originally Posted by Grady View Post
If an A50 were connected with no load, such as just checking for continuity, it will be damaged.
I think that's probably what my contractor did to ruin the first 2
 
 

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