I serviced my expansion tank because of the releif valve, although


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Old 02-06-13, 11:13 AM
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Roll out and blocked vent safety switch

I just purchased a roll out switch. There are 2 of them and they look the same. One on the bottom and one on the top that had to be bypassed temporarily. I am assuming the top one is the blocked vent safety switch and the bottom is the roll out switch. At what temperature is this safety device supposed to shut off the boiler at? I read somewhere that it could be as high as 350 degrees which eventually may damage the radiant heating system, etc.

If it is this high is there a way to lower the bypass. Aquastat set to 180 degrees. Part # AQ02101 is the model # of the switch on the Utica Boiler.

Thank you.
 
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Old 02-06-13, 02:16 PM
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What's going on with your system? You sure seem to be having one problem after another...

We need the 'back story' on this... WHY did the rollout switch need to be bypassed?

These are SAFETY devices that protect your home from FIRE in the event that the chimney, flue pipe, or heat exchanger in the boiler become blocked.

When a SAFETY switch trips, the entire system MUST be examined to determine the cause of the trip. You can't just say "It's a bad switch" and simply replace it. That is literally "playing with fire".

The temperature setting of these switches has NOTHING at all to do with the water temperature in the system.
 
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Old 02-06-13, 08:13 PM
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The boiler was examined by a qualified professional and for some strange reason the aquastat went bad and along with the wire harness and at the same time I had him change the vent damper (just because it would be less expensive now then have the vent damper changed later). We found out that whoever serviced the boiler last bypassed this roll out switch. He said that the switch needed to be replaced. So I finally finished replacing the switch (very easy) and now the boiler works like a charm without the bypass. Kicks out at 185 degrees and comes back on either around 160 or lower depending on the demand for heat. I just spent one hour watching the temp. guage with the whole house running on heat. It is very hot and everything looks good. There is nothing else bypassed.

The expansion tank is next as it seems that is water logged. I am still waiting for the plumber to show up to replace that. It is like pulling teeth.

The end switch on one board was a fluke and I am either replacing the same board or getting a new one. For now I have that sent to another board and everything is working fine.
 
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Old 02-07-13, 05:22 AM
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You have a radiant system that runs at 185??? The flame rollout switches are set at a high temp but you gotta remember thats not water temp, if e flame happens to roll out and continuously engulf the roll out switch, its a matter of seconds before it heats up enough to trip. Even with out flame rollout, it tends to be pretty hot at the safety switch location due to the fire being about 6 inches away
 
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Old 02-07-13, 05:48 AM
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That is my concern. I want to make sure that the boiler (if it does not shut off at 185 degrees) eventually will shut off at about 220 degrees and not at 350 degrees. The system can handle 250 +, especially through the radiators and tubing. Although the radiant heating system is rated for 225 (pex tubing) and may cause damage. Luckily, the heating system is in the sub floor and not underneath the tiles. The transfer plates really do help to distribute the heat so there is for the most part even heat. The only problem is the original radiant has only 1 tube through each joist while the Family room (open to 2nd floor) and 400 square feet has 2 tubes through each joist making it more efficient & also has radiators in the room. So the heat in each rooms run kind of crawls into the other rooms making the house extremely comfortable.

I just want to make sure that the hot water in the event the aquastat fails eventually shuts downs the system. And to answer some of your questions:

You have a radiant system that runs at 185??? No, the radiant heating system will run at about 140 going in and about 120 coming out. There is a mixing valve that helps to maintain the temperature. I have been advised to run the system at this temperature. Unfortunately, I can not lower the temp. any amount on the aquastat. Starts @ 180. The original one started at 160 or 140 I believe.


The flame rollout switches are set at a high temp but you have to remember that’s not water temp, if e flame happens to roll out and continuously engulf the roll out switch, it’s a matter of seconds before it heats up enough to trip. Even without flame rollout, it tends to be pretty hot at the safety switch location due to the fire being about 6 inches away

I believe that I do understand the e flame and yes the area gets pretty hot. If the aqustat fails to shut down the boiler, are these roll out switches (2 of them) designed to shut down the boiler? If so, what water temperature (approximately) is that equivalent to? My concern is not to damage the system
 
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Old 02-07-13, 07:01 AM
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are these roll out switches (2 of them) designed to shut down the boiler? If so, what water temperature (approximately) is that equivalent to?
There is no 'approximate' temperature of the water when a rollout switch trips.

You could have rollout on a stone cold boiler, or on a hot boiler.

Water temperature is controlled solely by the aquastat, not any of the safety shutdowns.
 
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Old 02-07-13, 08:12 AM
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Is there any device that you are aware of that will act as a secondary shut off if the temperature becomes to hot and the Aquastat fails (for some strange reason). Or will the boiler just continue to heat up.

I am always concerned after the boiler did not shut down last time. I will consult the professional when he shows up next month. Thanks!
 
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Old 02-07-13, 08:46 AM
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Yes, one may install an 'Auxiliary High Limit' which would provide a redundant backup to the existing primary control.

These Aux High Limits should have a manual reset pushbutton on them that would require operator action to restore operation. Many are installed as self-resetting units though... which I guess is OK... may or may not pass an inspection by code official...

Thing is, a MANUAL reset would alert the homeowner that there was some problem that needed addressing. If the control automatically reset, the system could continue to run apparently normally with no notice by the homeowner that anything was amiss.
 
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Old 02-07-13, 01:37 PM
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Knowing that I have the Honeywell Aquastat and other controllers, this auxillary limit switch (Where can I purchase this) and which one should I purchase?

Exactly how is it hooked up? How does it sense the temperature of the boiler, etc. It is hooked to the boiler? With the aquastat? Thanks!
 
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Old 02-07-13, 02:52 PM
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Although the picture attached to this product page does not show the manual reset, the description says that it IS manual reset. If you are adding an aux high limit, I recommend you go with the manual reset model.

L4006H1004 - Honeywell L4006H1004 - High Limit Strap-On Aquastat, 100-240°F range, Manual Reset

This particular one is a 'strap on' part that includes the hardware for mounting on a pipe. This would typically be the hot supply pipe out of the boiler, as close to the boiler as possible.

There are a number of ways to wire these.

Perhaps the easiest way for your boiler would be to wire in series with the existing 'safety' rollout and blocked vent switches. This would cut power to the burner and shut the flame down just as the other safety switches would.

After installation you would set the temperature of the auxiliary high limit about 20-25 F ABOVE the high limit in the aquastat...
 
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Old 02-08-13, 06:58 AM
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It looks like the sensing bulb would be strapped on to the hot side of the boiler (closer to the boiler) and this would be hooked up parallel with the aquast and set 20-25 degrees higher than the boiler @ 200-210. I have a thermostat and will check the temperature of the pipe coming out at this point to determine the temperature.

Well, I just checked the temperature and the temperature is a few degrees off. I ran the boiler to 220 and the temp was at 200.

Is this item hooked up to the aquastat or the safety controls on the boiler (2 Rollout switches) or possibly even the Intermittent Pilot Control? It is a 24 volt or 120 with a transformer built in?

I will read the manual to determine. Thanks!
 
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Old 02-08-13, 07:12 AM
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and this would be hooked up parallel with the aquast
No, not in parallel with the aquastat.

In SERIES with the ROLLOUT and the BLOCKED VENT switches.

Set the boiler operating aquastat at 180 and the auxiliary at 200-205.

It is a 24 volt or 120 with a transformer built in?
You will be connecting it to a 24 VAC circuit (the rollout and blocked vent switch circuit is 24VAC), and no, there is no 120VAC or transformer required.

There are only going to be two low voltage wire connections to this aquastat.
 
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Old 02-08-13, 07:34 AM
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In SERIES with the ROLLOUT and the BLOCKED VENT switches.Set the boiler operating aquastat at 180 and the auxiliary at 200-205. Sorry, but what is in series. I have 2 wires running to each roll out Switch. One for the blocked vent (up top) and one on the bottom. (I am learning). Somehow it sounds like it is cutting the power off to one of these switches? I know when I replaced the roll out switch and had to remove the wires everything was cut off.

You will be connecting it to a 24 VAC circuit (the rollout and blocked vent switch circuit is 24VAC), There are only going to be two low voltage wire connections to this aquastat. I read the instructions and they are as confusing as they are written.

And BTW, I just charged my expansion tank (which had absolutely no air in it). Was not water logged at all? Your instructions worked like a charm. The boiler technician said the tank was water logged. I guess I just saved $165 and will never call these people again. They could of easily spent 10 minutes (that is all that it took) to charge the tank properly or check it out. The water was stone cold and draining pressure on the boiler would have taken 5 minutes. Thanks for that Sticky Note on servicing the expansion tank.
 
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Old 02-08-13, 08:21 PM
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I serviced my expansion tank because of the releif valve, although

Originally I was spitting out about 2.5 gallons per day from the 30 psi relief valve. After following the instructions and putting in 13 psi, the problem seemed to go away. Although I am kicking out very very very little water into a bucket. I would say in the last 6 hours about 3 ounces of water. My tank had absolutely no air in it.

Is it possible I lost some air in the process of turning the system on? Should I check the air again? The PSI has not reached the 30 mark and the water seems to be spitting out between 20-25 psi. Originally after charging the tank I was between 15-20 psi. Now I am at about 25 psi. What should I do? The relief valve was changed out about 2 years ago. Should I shut off boiler and follow the instructions again? Is it possible that the tank needs more air pressure then 12-13 psi? Just curious? Thank you.
 
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Old 02-08-13, 09:59 PM
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Didn't you have another thread going on with the same problem

The valve is rated for 30 psi......but it can open a few pounds earlier. I'm not one of the boiler guys but your system pressure should be under 20 pounds I believe.

I wasn't following your other thread that close but in this thread it sounds like your fill valve is over filling your system.
 
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Old 02-09-13, 09:09 AM
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Have had many threads with so called different issues. All fixed for now. Aquast, wire harness, vent damper, roll out switch & cirucuit board. I guess my luck finally ran out. Everything went at once. I am ready to go downstairs and check the pressure of the tank for air and fill up again to determine if leaking air. Will find out shortly.
 
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Old 02-09-13, 12:49 PM
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what is in series?
Series is when the connection is from one, to the other, to the other, etc... like christmas lights... one goes out, they all go out.

Let me try this, this is series... wire from point A to one connection on rollout, other connection on rollout to one connection on blocked vent, other connection on blocked vent to one connection on aux high limit, other connection on aux high limit to point B...


A---------------rollout----------------blocked vent--------------aux high limit------------B


If they were being wired in parallel it would be like this, and NOT what you want.


A----------------|---------------------|----------------------|
....................rollout................... blocked vent.......... aux high limit
B----------------|---------------------|----------------------|

I'll post a graphic of how you need to wire this, I think that will make it clear.

I just charged my expansion tank (which had absolutely no air in it). Was not water logged at all?
Yes, it was waterlogged. If there was no air in it, there had to be water. Waterlogged does not mean that water will come out the air vent...

How many times did you have to repeat the steps 5-8 ?
 
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Old 02-09-13, 01:23 PM
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This should make it all clear.............

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Old 02-09-13, 01:54 PM
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There was no air in it because I have never seen anyone ever add air to the expansion tank over 10 years (This is what I believe happened). Could the tank be waterlogged (possibly)? I guess only time will tell. If so, maybe in about 2 weeks there will be more water coming out of the relief valve.

There was a boiler person who replaced the relief valve. Ever since I added air the boiler will only creep up to 25 psi max and not 30-35 and there is a few ounces spilled out of the boiler (not 1/2 gallon per day on a cold day).

Steps 5-8 were repeated about 4 times until I finally had about 13 psi in the tank. I do not believe there is air in the system as I have these flow meters for the radiant heat (kind of all connected together) that are not showing any bubbles at all.
 
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Old 02-09-13, 01:56 PM
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Dom, I suspect several things...

1. Your pressure gauge is not accurate.

2. Defective expansion tank in spite of seemingly OK... these can be tricky devils. A bad tank can seem to be good... if after charging the tank the problems re-appear suspect a bad tank, OR...

3. As PJ said, possibly a fill valve that is leaking through internally.

Follow the step-by-step instructions for charging the air in your in this post to the LETTER... do not skip or skimp.

http://www.doityourself.com/forum/bo...sion-tank.html

Also, if your gauge is inaccurate, you might as well be spitting into the wind, VERIFY IT!

http://www.doityourself.com/forum/bo...ure-gauge.html
 
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Old 02-09-13, 01:58 PM
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I am kicking out very very very little water into a bucket.
There should be ZERO water coming out the pressure relief valve.

Follow instructions above to verify the boiler pressure gauge.
 
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Old 02-09-13, 02:10 PM
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NJ Trooper:


The wiring seems pretty straight forward. We are just creating a loop. So if the power on the high limit switch cuts off (24 volt) then everything shuts down. I will order the part from Pex Supply first thing in the morning. I also ordered 4 spring thermometer's for the pipes.

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Old 02-09-13, 02:41 PM
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There was no air in it because I have never seen anyone ever add air to the expansion tank over 10 years (This is what I believe happened). Could the tank be waterlogged (possibly)? I guess only time will tell. If so, maybe in about 2 weeks there will be more water coming out of the relief valve.
Here's what happens when a tank runs for a long time with improper air...

The rubber bladder inside the tank gets stretched way out of shape because of no air. It's not supposed to be stretched that far really. When the system cools down to it's 'minimum', there is to be very little water in the tank, and the diaphragm is in it's 'neutral' position.

When there is not enough air charge, the diaphragm never goes into neutral position and in fact is stretched way out in the opposite direction.


image courtesy emeraldinsight.com

This pic shows a cross section of the tank so you can see what I'm talking about. If there is no air in the tank, that rubber diaphragm is stretched all the way to the bottom of the tank.

If that tank is 10 years old, I have little doubt that you should simply replace it.

And add the optional valves shown in the sticky post.

I'm going to merge your other thread that you started recently with this one ...
 
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Old 02-09-13, 03:02 PM
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As always thank you for your continued help! Appreciate everything you are doing.
 
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Old 02-13-13, 04:49 PM
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Well finally installed the Auxiliary High limit switch. Works like a charm. Although aqustat set for 180 and the Aux set for 120 and as water became hot, the Aux High Limit tripped. So I increased the temp from 120 to 140 and then reset the red switch. Gas fired up and I patiently waited until the High Limit tripped. Then I increased the high limit to 160 and waited patiently. Nothing tripped on the High Limit because the aquastat shut off at 180 (based on boiler gauge). So in turn I increased the temperature on the boiler and the boiler temperature increased to about 195-200 degrees before finally the High Limit tripped. The sensing tube is flush against pipe. I made sure that I slowly pressed the tube against the pipe as I tightened down the strap. I would like the system (if fails to shut down at 210 on the aqustat) but the High Limit needs to be about 165-170.

Questions:

Is it possible that the boiler gauge is off? Aquast is brand new. And boy is the water hot at 200 degrees. You can tell just by touching the Pex Tubing. I would not test any further.

Is it possible that the aquastat is sensing the wrong temperature in the well?

Is it possible that the gauges on the pipe are off? The gauges are brand new. The pipe sure seems hot. I tested all 3 guages (all reading the same temp). All brand new. Although 20 degrees lower then the older Clifton guages (new ones are Winter thermometers)

Should the pipe be the same temperature as the boiler water? Coming right out of the boiler being pushed by a circulator pump and sometimes more than one?

Thanks!

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Old 02-13-13, 07:05 PM
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Is it possible that the boiler gauge is off?
Yes it is.

Aquastat is brand new. And boy is the water hot at 200 degrees.
Yes it is!

You can tell just by touching the Pex Tubing. I would not test any further.
Wise choice. Upper temp rating on the PEX is probably very close to where you are operating it at 200.

Is it possible that the aquastat is sensing the wrong temperature in the well?
If the bulb is not FULLY inserted in the well, there could be a difference.

One thing to understand is that INSIDE the boiler, the water temperature can vary from where the well is inserted into the boiler to any other point inside the boiler. This includes the exit temperature from the supply pipe. The water inside the boiler is never uniformly the same temperature throughout the boiler.

Is it possible that the gauges on the pipe are off? The gauges are brand new
Probably not.

Should the pipe be the same temperature as the boiler water? Coming right out of the boiler being pushed by a circulator pump and sometimes more than one?
Not necessarily. See comment above...

I would think that it might not be all that uncommon to see maybe a 20° difference between the aquastat setting and the water temp at the supply outlet.

The other thing to note is that the outside of the pipe will never be as hot as the water inside the pipe because the surface of the pipe loses heat.

If you insulate the pipe about a foot above and below the point where the aquastat is clamped on, it will help. You might even try and place some insulation between the bulb and the body of the AUX aquastat to prevent that from sucking heat out of the bulb.

This goes for the thermometer locations as well.

The bottom line is that these settings are to a large degree ARBITRARY. The ultimate ACCURACY is not something to spend a lot of time worrying about.

As long as the controls will operate REPEATABLY at the same temperature every time is the most important thing.

I would start with a well insulated thermometer right at the boiler outlet pipe. Adjust the MAIN OPERATING aquastat without regard to it's actual dial setting to shut off where you want it to, even if the dial reads differently from the actual thermometer reading.

Then, at that point, turn down the AUX high limit until it trips the burner off. Make note of the dial reading and set it about 20° higher than the point at which it trips.

Any device that clamps to the outside of the pipe is not going to be as accurate as one inserted into a well. But that doesn't really matter, as long as it shuts off when you want it to.
 
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Old 02-15-13, 06:49 AM
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Update to the High Limit Aquastat. The unit came with this foam (rubber type of material) that the sensing bulb is tucked inside. After using this rubber foam gasket, the High Limit and Aquastat on the boiler are within 10 degrees of each other. This ensures that the bulb is toching the pipe coming off the boiler.

Before, they were over 35 degrees apart (lower temperature on the pipe). The aquastat was set to 200 (only ran through copper tubing). The Aux was set to about 200. As it reached 200 degrees, the safety device tripped. Without the rubber insert (I am assuming that is what it is for) tucked inside the housing and bulb tucked inside that. Only the outside is exposed to the pipe, the temperature was way off.

Although my winters thermometers are still showing surface temperature at 150 vs. 200 on the boiler and High Limit tripped at 200. The shutdown is 180 on the boiler in which the gauge runs to 185. So I can safely assume that if the aquastat fails at 180 degrees, and the house is calling for heat that once the boiler reaches 200-210, the secondary safety device will trip. I do like the manual reset option as you will know that your aquastat did not shut down at 180 and the problem will not continue.

Again, thanks to NJ Trooper for all his help. I probably saved about $500 on this project.
 
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Old 02-17-13, 12:57 PM
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rollout

just a fyi, the AQ02101 is a manual reset rollout/spill switch that opens at 290*F
 
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Old 02-17-13, 01:11 PM
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That is good to know. I thought there was a limit to the rollout switch. But how does this switch sense the temperature? It is just hanging in the boiler. At 290 *F, the pex tubing may have already failed and the tiles would of possibly become damaged. Chances are that the radiators can handle that temperature. If the whole house is calling for heat, it does take a while for the water temp to reach a very high limit. But if only one zone is calling for heat, the temp from 180 to 290 may only take 10 minutes. This is why I like the Aux High Limit. Also the lower the unit is to the boiler on the pipe, the faster it senses the heat. It took a while to figure out the best temperature and I tested it a few times. 210 on the boiler shutting down the until at 200. 30 degree difference. This should not cause any damage and protect the system.
 
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Old 02-17-13, 01:20 PM
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Rollout/spill

the flame rollout and spill switches dont sense water temperature. they sense ambient temp above the burners and in the draft hood. if an unsafe condition were to occur due to a blocked vent condition or a plugged up heat exchnger, these saftey devices would trip.
 
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Old 02-17-13, 01:59 PM
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I thought we were clear on that point already...

Cat, what Todd said is absolutely true... the rollout and blocked vent are measuring temperatures inside the boiler itself... AIR temperatures more or less, and have NOTHING whatsoever to do with the WATER temperatures.

If your chimney or flue or the flue passages in the boiler were blocked for some reason, the HOT FLUE GASES would 'spill' out of the atmospheric vent, or from around the burner area. These hot gases are what would trip these switches.

Again, nothing at all to do with water temperatures!
 
 

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