My Hurricane was hit by a tornado

[Tom and Pam Brown]

It could be that your thermostat is bad and not calling for heat. If you have the 4 button thermostat it could have issues.  It seems the stat is calling for heat since it kicks on when you delete the hot water from the system.

Just a thought.

[Edward Buker]

Joel,

That certainly tells more of the story. The Aqua Hot does not have any of the conventional Aquastat controllers that standard boilers use.

 If the only thing that fires the burner is a single output from the Aquastat you could put a voltmeter on the input to the burner from the Aquastat, that fires the burner, and see when and if voltage is applied and how the burner responds. At the same time you can call for heat using the room circulators, via the thermostats, and use an IR gun to monitor the tank temperature. Alternately you can do the same with water demand and see if the thermal shock is triggering the firing and not the circulator loads as you pass through the burner on temperature range. These measurements and how repeatable they are should tell you what is going on.

 The Aquastat does sound like the culprit. The good news is that may be a standard item that is available from a plumbing supply house....maybe.

Later Ed

[Joel Weiss]

Ed--
Those are good ideas; I'll be trying them.  Even if I have to buy the aquastat from ITR it can't be all that expensive.  Since the problem is intermittent I may just replace it anyway. Trying to diagnose an intermittent is often so frustrating and time consuming it's just easier to throw some money at the problem. LOL
Joel

[Edward Buker]

Tom,
I think the thermostats are working given Joel says that the circulators start. In most systems using boilers in RVs that is all the thermostats control. The boiler temerature controls the burner and electric elements.

Joel,
Aquastats that I have worked on from my days living in the NE had contactors in them that would click when the probe temperature set points were passed. They are mechanical devices and can become worn and intermittent. You may be able to aim the IR gun near the Aquastat but any good metal boiler water jacket location that is close should be useful. I have used the metal filler neck on my Aqua Hot for these kinds of checks when I did not want to spend a lot of time pulling access panels. May not be as precise for measurements but may be good enough. Good luck and keep us posted.

Later Ed

[Dick Simonis]

Joel, it looks like there are three (3) aquastats in the boiler assy.

One for normal operation....on at 149F and off at 167F.
one for High level open at 190F manual reset
One for overheat at 205 manual reset.  This one is in line with the fuel pump.

There also appear that there may be an aquastat on each air handler.  These appear to be in series with the fan moter and have the abiltiy to be bypassed.  Guessing they are used to disable the fan unitl the heater core is up to temp if you so desire.

The aquastats in the boiler all use a common isolated ground so if the problem is intermittant, that might be a good place to look.  The fact that the WH will cycle the flame on and off is a bit bothersome as it appears any of the boiler aquastates take prioity so if any of them were open the unit should not respond to any zone request for heat.

It almost sounds like the controller is not honoring the heater zones request but is honoring the HW zone.

There are some test point in the controller for each aquastat so you can at least test them easily.  5VDC open, 0 VDC closed.

Good luck and waiting to hear the resolution.

Dick

[Tom and Pam Brown]

Ed,

just thinking the thermostat could be a problem I had issues with mine and had it rebuilt and at least that issue was gone.  It might be a good idea to check the connections on the back of the thermostat just in case.

Good luck!

[Edward Buker]

Tom,

I'm the first to admit that I do not know the ins and out of the Hurricane systems. Dick mentions three Aquastats in the system and I am not sure how thay are all wired in and the roles they play. My guess is that the 149/167 Aquastat is supposed to control the burner. The issue is the burner firing and what powers that and is it repeatable and functioning properly. Hope Joel can figure out what controller controls the burner and gets to the bottom of this.

Later Ed

[Joel Weiss]

I'm pretty sure that my system does not have the aquastats that control the fans; they start the moment the thermostat calls for heat.  Both thermostats in the living area seem to work fine with respect to turning on the circulating pump when heat is called for.  My ability to use the hot water tank to force the system into operation is not totally reliable; it didn't work tonight but it might by morning.  That doesn't prove anything one way or the other.

After I speak to ITR on Monday, I'll probably just gamble and have them send me a new 149/167 aquastat.  When I was a practicing scientist I was an experimentalist.  That's a fancy way of saying I like to stick things in the experiment to see what happens.  If the aquastat fixes the problem, wonderful.  If it doesn't then the issue is most likely more complicated since it means the system is not responding to the call for heat which may imply circuit card issues.  That may require more expertise than I currently have available; the good news is that I plan on spending the summer in the NW and ITR has already said they do factory service.

[Edward Buker]

Joel,

I found a schematic on the web for a hurricane system and it is quite a bit different then my Aqua Hot. All of the burner drive functions seem to reside in the controller board. There appear to be aquastat switches for the inside the coach fan heaters but they do not have any function other than to kill the fan if there is no heat present and just open the ground line to the heater fan. They have no feedback function to the Hurricane unit.

If you locate the isolated ground terminal strip and connect a wire to it and take the other end to position 6 on the terminal board strip where the green/black wire is connected it should fire the burner. This is bypassing the operating Aquastat that closes at 149 and opens at 167 degrees. If your unit is below 149 and it does not fire then check to see that the orange wire on position 5 is grounded to the isolated ground strip by connecting the wire there. If the unit fires on position 6 the operating Aquastat is bad. If it fires with the temporary wire touching position 5 then the high limit Aquastat is bad or needs to be reset. Neither of these checks should be done by screwing a connection in place at the control board terminal end. You should just hold the wire in place for a short period of time to do checks. If either connection causes the unit to fire repeat that test enough times to conclude that the result always causes proper operation of the burner to know that the control board is not intermittant also.

If neither one of these checks causes the burner to start and fire then it is likely the controller board. I used the schematic in this manual, verify that yours uses the same schematic and pins before running the tests. Hope this helps...Later Ed

http://itrheat.com/wp-content/uploads/2011/08/HurricaneSCH25ManualRevFeb2011_0021.pdf

[Dick Simonis]

Ed, I think your assesment is correct and the schematic available on line corralates with my Hurricane which should be indentical to the one Joel has....same model and year.  If indeed his HW heater is also intermittant than the operating aquastate is the probable culprit as it controls the burner with priority over zone inputs.

I haven't seen the boiler aquastates, but I'm almost betting they are simple surface mount bimetal units similiar to what is used on the Sealand for the electric heating element. Trouble is, the boiler needs to be removed to access the things.  He will get to replace his anti-freeze again.

If the unit would consitently fire up properly from a cold start I would put the operating aquastate at the top of the list.  Easy for those to get "sticky" in the open position.

[Edward Buker]

Dick,

Hope Joel can find what is causing him the trouble. I also thought about a burner motor stopping on a bad spot on an armature but it would seem that would stay in place and not restart. I think that is a remote possibility but he could check the output wire  from the controller board to what they called a blower to see if 12v or ground is being applied if he is in doubt. Whichever the board is using, breaking ground or applying 12v to turn on or off the blower.

Hope my shot in the somewhat dark gets lucky and hits a culprit....

Later Ed

[Joel Weiss]

I haven't seen the boiler aquastates, but I'm almost betting they are simple surface mount bimetal units similiar to what is used on the Sealand for the electric heating element. Trouble is, the boiler needs to be removed to access the things.  He will get to replace his anti-freeze again.

Can someone clarify what is involved in removing the boiler?  I don't refilling the anti-freeze because what we have in there at the moment is largely water with some re-used anti-freeze.  Kevin at ITR said we could use water until we were sure we had really fixed the leaks.  There's no risk of freezing where we are so that's not a concern.

With respect to the boiler I know the water jacket is removable, but do I have to pull the entire Hurricane box out to get to it? I have a terrible feeling that is what has to be done.  

[Dick Simonis]

When I replaced my HW heater I looked at furnace assy and thought this isn't too bad to remove but still, there is the wiring, fuel, exhaust, and etc.  I didn't see the aquastates when I opened the front panel looking at the burner stuff, so yeh, I reckon it will have to come out.

Personally, if I were doing it, I'd look at pulling the HW heater and the board it sets on as well.  Not that it's necessary it's just that I don't bend as well as I used to and it would really open up the enclosure.  FYI, removing the HW heater takes about 15 -20 minutes.

Alternativily, I would simply pay someone, set back with a beverage, and learn for the next time.

[Joel Weiss]

Alternativily, I would simply pay someone, set back with a beverage, and learn for the next time.

This is what I plan to do.  I have a decent tech working on it here in Port A; if he doesn't think he wants to do it I'll take it to ITR in a couple of months.  The nice thing about being in a relatively warm climate is that our two electric heaters are quite capable of keeping us warm and the electrical changes we made give us two separate circuits to plug them into.

[Dick Simonis]

Joel, one last thought occurred to be last night.  I realized that the air handlers run independently of the furnace.  In other words, if the thermostats are calling for heat, the fans will run even if the remote switch in the coach is turned off.  The remote switch connects to the brain with (according to this version of the manual) a telephone type connector and if this circuit is interrupted the systems would be exactly what your are experiencing.  It might be worthwhile to check this connection.  There isn't any good circuit diagrams of the remote switch but I suspect that the indicator light on the switch panel would be out during the occurrence of a problem.  Also, the switch panel does have an alarm that sounds if any internal problems occur.  The fact that you system did not enter an alarm condition really suggests something simple.

If you look at the brain box, there is an indicator light that shows if the remote switch is on and (I believe) a light that says remote is off.

In keeping with the KISS principle, this would replicate your symptoms perfectly.