Kabola not heating rooms but heating water

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Streff

Senior Member
Joined
Oct 13, 2019
Messages
133
Location
USA
Vessel Make
Californian 45 MY
All room thermostats related to the Kabola system stopped triggering the fans at the heat exchanger. The kabola works fine, heats water as normal, the cooling lines are boiling hot at the heat exchangers but the fans are not being tuned on. I tried setting the thermostat 4, 7, 10, 12 degrees above ambient.. I hear the thermostat click as if it is starting a heating cycle but the fans do not activate.

I checked all fuses inside the kabola box, I switched thermostats between rooms, I applied external power to the fans and they run fine.. the only things I noticed is this.. when I remove the front of the thermostat, the voltage in the wires going into it is negative (-12V for example).. since its the same scenario at all thermostats I am thinking that it’s normal?

I would very much appreciate any and all input and suggestions.

Streff
 
The voltage can not be negative. If you run it through your meter backwards it will read negative.

How are you reading 12v. With a multimeter or is the thermostat reading -12v?
 
The voltage can not be negative. If you run it through your meter backwards it will read negative.

How are you reading 12v. With a multimeter or is the thermostat reading -12v?

Hello, I am using a multimeter, running it the correct way I believe. :)
 
If you are reading -12v then you are running the meter backwards to the current.

Obviously you have voltage to the thermostat. Now you just need to follow the voltage to see where the break in the connection is occurring. Some were between the thermostat and the fan there is a break/switch/fuse that is preventing the current from flowing.
 
Thank you for the reply. Since all 4 thermostats are not triggering their corresponding fans, I am thinking that something is off in the main control box. There are several fuses in the control box, I checked them all. But I will try swapping the main fuses out and see.

Normally during the summer, we only use the kabola as a water heater, except last year in Alaska where we used it to heat the flybridge. We are currently near desolation sound in BC and we have had cool temps and consistent rain for the last 4-5 days leading to pretty cool evenings.

Streff
 
Thank you for the reply. Since all 4 thermostats are not triggering their corresponding fans, I am thinking that something is off in the main control box. There are several fuses in the control box, I checked them all. But I will try swapping the main fuses out and see.
I think you're on the right track.

I can't speak to Kabola, but my ITR system has three different DC power sources, each with its own circuit breaker. One of them is for the fans.

Since you're getting circulation in the heating loop I'd assume that the thermostat is working. In my system a call for heat from any thermostat starts the heat loop circulation and switches the corresponding fan on.

Do you have a wiring diagram for your system?
 
Thank you for the comment, Jeff. I have the printed manual and bits and pieces from the Kabola site but no clear diagram. Interestingly, our Kabola sends heated circulation everywhere, regardless of thermostat status. There are manual cutoff valves near the main unit to stop circulation in the loops that are not needed. So it seems not as sophisticated as your ITR system.

In the control box, There is a solenoid for each heating area and one for the water heater. Its unlikely all solenoids have gone bad (except for the water heater).. so something else is at play.
 
Sounds like your thermostat operates a relay that puts power to the Solenoids. I'm guessing the main power to the solenoids is turned off. Possible that you have several bad relays but less likely. I would follow the solenoids power wire back to these relays and see if you have voltage on the other side of the relay. I'm betting you do not. You probably have an unmarked circuit breaker that is off because you are unaware of its purpose.

The thermostats appear to be getting power from a different source than the solenoids.
 
I would check to see if there’s an aquastat that keeps the fans from turning on till the water comes up to temp. If it has one and it’s malfunctioning you can bypass it and the fans will run off the thermostats.
 
Our Kabola is equipped with Summer / Winter Loops, which has solenoids to prevent water flowing to the remote air handlers (in the summer loop), but still heats the hot water tank...I assume this is to lessen total run time on the furnace. Ours also has a switch to select summer/winter mode, perhaps yours has been pre-wired for this feature, and has somehow failed internally?
Good Luck.
 
Sounds like your thermostat operates a relay that puts power to the Solenoids. I'm guessing the main power to the solenoids is turned off. Possible that you have several bad relays but less likely. I would follow the solenoids power wire back to these relays and see if you have voltage on the other side of the relay. I'm betting you do not. You probably have an unmarked circuit breaker that is off because you are unaware of its purpose.

The thermostats appear to be getting power from a different source than the solenoids.
I think this might be zeroing in on the problem. It is possible that you have two breakers, one for the boiler and one for the fans/heat exchangers in the living space? And even if there is a single 12 or 24V panel breaker, on the Kabolas that feed either and internal (older models) or external (newer models) inverter that produces 230V 50hz to run the boiler. I would expect a branch off of DC feeding the inverter to them power the air handler fans, assuming a single breaker setup. That branch circuit likely has a secondary breaker or fuse.
 
Thank you all for the insightful comments and feedback. I first tried the idea of the Aquastat without success. I looked hard but could not find hidden breakers or fuses. I checked all the relays and swapped them around without success. I opened the front control panel and checked all connections. The relays light up and is triggered appropriately when the thermostat clicks and calls for heat but the signal does not reach the fans. I checked again all fuses in the control box.

There is a time delay relay that controls the pump. I have it set at 150 seconds (max is a 180 sec). It has acted erratically in the past from vibration but I had secured it tight with a small mechanical tie 2 years ago and it’s been working fine since. I giggled it around and held it tight, to see if it somehow has an influence on the fans, again with no success.

The unit is a 24V unit but the fans at the exchange are 12v. Four years ago the pump was acting up but it was the Time delay relay that was screwy and susceptible to vibration. I still installed a new pump just to be sure. I did buy the kit to convert the unit to 230v. This was during the pandemic and the needed solenoid could not be sourced. The unit has been running fine as original on 24V, so I did not pursue the conversion to 230v.

We are hoping to be near Delta marine in BC next months where I try to get them to look at it. Delta marine are so busy that it’s almost impossible to get an appointment on short notice. Maybe try a dealer to do a virtual consultation for a fee. I think that it's something simple (as many have said a breaker or fuse) but I am at a loss right now.

Thank you all for the advice and comments

Streff
 
In various systems I’ve had through the years on occasion have had an airlock or gunk in the circulating loop. When you say coolant is hot wonder where you checked it. Is it hot at all the registers? Is flow strong and good. If not problem maybe due to an airlock or partial block and not the other components. Would hit the bleeder on the last one in the loop and see if you get good flow or at least check temp at its feed and return. Have gotten confused in the past when circulation isn’t completely blocked or intermittently. Circulation is now first thing I check and it’s the problem most of the time.
 
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I would turn on the system. Then I would check the heat exchangers to see if they are getting hot. This would rule out any issues related to circulation. If the heat exchangers are not getting hot, I would assume that there is an aquastat preventing the fans from coming on.

If the heat exchangers are getting hot I would then follow the thermostat wire to see what it is energizing. This would lead me to the component that is preventing the electrons from flowing to their appointed rounds.
 
Can you post the model number of the system and thermostats? Functionally these are pretty simple systems but there are a lot of different ways to accomplish the end result.

The basic steps being;
1) Heat the water
2) Move the water
3) move air across the coil

Sounds like the first two are working.
 
Thank you all for the great input and comments. I am back working on the Kabola issues after we got back to the boat after spending a few days at friends’ condo in Vancouver. Other than a broken phone screen, a very nice city to visit. Luckily I have a really old iPhone as backup and it still works with the SIM.

I checked the various points that were mentioned. Yes, I do hot coolant at the distal heat exchanges. I traced the 12V wires that energize the fans and they all come from the central control box. All connections and fuses in the control box are okay. I even opened the face on the Kabola and checked the corresponding connections to the pump and to the control box.

Wires from the thermostats go to the relays in the control box. When the thermostat asks for heat, the corresponding relay is activated and light up as expected.

So it seems that the communication between the relays and the fans is faulty for all zones? The water heating function works perfectly and is activated automatically as soon as the Kabola is turned ON.

I have attached a photo of the unit and control box.

Even though it’s warmer now, we hope to cruise to Tofino & broken islands which could still be pretty cool at night.

Again, thanks so much for the help.

Streff
 

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I'm guessing that fuse block contains the fuses for each of the fan units. Assuming a 12V system....

Is there 12V power & ground at the input to the fuse block? The red wire with an inline fuse holder appears to be the feeder power. If that doesn't have power then non of the fan units will work, just as you are experiencing.

Work upstream or down stream based on what you find. The symptoms say the power disruption is in the feed circuit to that fuse block. Check the inline fuse, actually removing the fuse. Meter the terminals in the fuse holder to see if there is power coming into the fuse holder.

Keep following it from there.

Also locate the ground for all the fan units. They should come together at some common point. That's where your negative lead should be.
 
I’m wondering about the time cube.
A search was done looking for aqua stats with none found. Is the time cube used to set the delay time for warm up before activating the fans?
A look at the schematic would help.
 
I'm guessing that fuse block contains the fuses for each of the fan units. Assuming a 12V system....

Is there 12V power & ground at the input to the fuse block? The red wire with an inline fuse holder appears to be the feeder power. If that doesn't have power then non of the fan units will work, just as you are experiencing.

Work upstream or down stream based on what you find. The symptoms say the power disruption is in the feed circuit to that fuse block. Check the inline fuse, actually removing the fuse. Meter the terminals in the fuse holder to see if there is power coming into the fuse holder.

Keep following it from there.

Also locate the ground for all the fan units. They should come together at some common point. That's where your negative lead should be.
I am with TT. Is there power on both sides of that inline fuse?
 
All room thermostats related to the Kabola system stopped triggering the fans at the heat exchanger. The kabola works fine, heats water as normal, the cooling lines are boiling hot at the heat exchangers but the fans are not being tuned on. I tried setting the thermostat 4, 7, 10, 12 degrees above ambient.. I hear the thermostat click as if it is starting a heating cycle but the fans do not activate.

I checked all fuses inside the kabola box, I switched thermostats between rooms, I applied external power to the fans and they run fine.. the only things I noticed is this.. when I remove the front of the thermostat, the voltage in the wires going into it is negative (-12V for example).. since its the same scenario at all thermostats I am thinking that it’s normal?

I would very much appreciate any and all input and suggestions.

Streff
Make sure you don’t have a “summer valve” flipped
 
All room thermostats related to the Kabola system stopped triggering the fans at the heat exchanger. The kabola works fine, heats water as normal, the cooling lines are boiling hot at the heat exchangers but the fans are not being tuned on. I tried setting the thermostat 4, 7, 10, 12 degrees above ambient.. I hear the thermostat click as if it is starting a heating cycle but the fans do not activate.

I checked all fuses inside the kabola box, I switched thermostats between rooms, I applied external power to the fans and they run fine.. the only things I noticed is this.. when I remove the front of the thermostat, the voltage in the wires going into it is negative (-12V for example).. since its the same scenario at all thermostats I am thinking that it’s normal?

I would very much appreciate any and all input and suggestions.

Streff
I’ve had two Kabola systems in my boats (wonderful product). When I encountered problems with the thermostats, always it was a dead AA battery inside the thermostat housing.
 

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