Raypak Boiler Not Working

[Buzzie8]

My floor heat boiler was working great until today. It will not come on. I noticed that the fluid was lower than normal in the window type glass next to the expansion tank. I noticed that if I pushed the small lever on the side that says push to test the pilot light will light and the boiler fires up. As soon as I release the lever the burner shuts back off. I tried to fill the system with more glycol from the fill spout and it would not take anymore. I was thinking that maybe it is not firing because it senses that the glycol is low. I tried filling it with both pump running and not running. But little to no fluid entered pipes and the the window showed a lower level than usual. I am calling the local Raypak dealer tomorrow but thought it might be an easy fix if I could get more fluid into system.

 

[Reds]

Did you try swapping out the thermocouple? If it's bad it will only let gas thru when you push the bypass button that you hold down to light it. When the Tcouple heats up it holds the gas valve open without holding down the button.

 

[Buzzie8]

Did you try swapping out the thermocouple? If it's bad it will only let gas thru when you push the bypass button that you hold down to light it. When the Tcouple heats up it holds the gas valve open without holding down the button.

I did not swap out the thermocouple, but I am wondering what the lever I am pushing on the side of the unit is. It says "push to test". I do not think this is the same bypass button that is located inside the boiler casing or is it?

 

[car washing systems inc]

Do you have a flow switch? It should be on the side of the unit could that be what you are pushing? If the switch is stuck it will not let the burner come on. Does your expansion tank have a cap on the top to fill.

 

[Buzzie8]

I am not sure if it is the flow switch or not. It is a small rectangular square attached to the right side of the boiler if your facing the unit. It has a green cover that when pulled off has a small latch type lever that says "push to test". When I push it the boiler immediately fires. It looks like a cone spiral spring of some sort that the lever is attached to. I will check further to see if the switch is stuck with contacts open. Does this detect the flow of the glycol? If so, could the contacts not be closing because the glycol level is too low? The pump is working and I know that there is some glycol based on the level indicator. I will check to see if there is a fill valve on top of the expansion tank. If so, OK to try and fill here instead?

 

[Bill Manke]

Sounds like the thing you are pushing on is a flow switch. Does it screw into the boiler. If so unscrew it and look to see if the flapper on the end is broke. If it is it wont sense flow.

 

[car washing systems inc]

I am not sure if it is the flow switch or not. It is a small rectangular square attached to the right side of the boiler if your facing the unit. It has a green cover that when pulled off has a small latch type lever that says "push to test". When I push it the boiler immediately fires. It looks like a cone spiral spring of some sort that the lever is attached to. I will check further to see if the switch is stuck with contacts open. Does this detect the flow of the glycol? If so, could the contacts not be closing because the glycol level is too low? The pump is working and I know that there is some glycol based on the level indicator. I will check to see if there is a fill valve on top of the expansion tank. If so, OK to try and fill here instead?

That sounds like a flow switch, the expansion tank should have a fill on the top if it is real low the switch may not get any flow, get the glycol to the line on the tank and then try, if that does not do it then pull the switch and see if the paddle is off. if it is not i would replace the switch.

 

[Buzzie8]

Thanks all for the info, looks like everybody is pretty much on the same page. I talked to Huron Valley Sales today and here are the troubleshooting steps he gave me:
1. Fill glycol level to about 1/3 up spy glass in expansion tank.
2. Bleed air out of system by running pump with each circuit in manifold being isolated.
This could fix system if not:
3. Open recirculation valve just a bit more
4. Make sure flow switch is clicking when pushed in, if not replace
5. Make sure pump motor is actually running and turning pump

If this doesn't work call local Raypak repair.

 

[Buzzie8]

Update: I filled expansion tank then purged air. Boiler still did not fire. I noticed that a small spring that is attached to an adjusting screw had fallen out. I reinserted spring and it still did not fire. I backed screw out about four turns and the boiler fired. Seems to be working OK now.

 

[Ghetto Wash]

Update: I filled expansion tank then purged air. Boiler still did not fire. I noticed that a small spring that is attached to an adjusting screw had fallen out. I reinserted spring and it still did not fire. I backed screw out about four turns and the boiler fired. Seems to be working OK now.

Be very careful that you didn't just adjust the flow switch to be "made" all the time.

 

[robtl]

Update: I filled expansion tank then purged air. Boiler still did not fire. I noticed that a small spring that is attached to an adjusting screw had fallen out. I reinserted spring and it still did not fire. I backed screw out about four turns and the boiler fired. Seems to be working OK now.

You quoted you filled the expansion tank then purged air? Where did you purge the air from, the expansion tank should be only less than half full of liquid and holding the rest full of air.

 

[MEP001]

Since you can't see the amount of liquid or air in the expansion tank, the proper way to fill it with air is to turn the system off and fill it to half the PSI of the ayatem's working pressure.

The water can permeate through the bladder over time. If you want to make sure it's properly filled with air, you can hold down or remove the Schrader valve and run the system until nothing comes out, then turn it off and repressurize the bladder.

This procedure has nothing to do with purging the air from the system.

 

[robtl]

Since you can't see the amount of liquid or air in the expansion tank, the proper way to fill it with air is to turn the system off and fill it to half the PSI of the ayatem's working pressure.

The water can permeate through the bladder over time. If you want to make sure it's properly filled with air, you can hold down or remove the Schrader valve and run the system until nothing comes out, then turn it off and repressurize the bladder.

This procedure has nothing to do with purging the air from the system.

Most boiler expansion tanks are not bladder tanks but just steel expansion tanks at a high point with the make-up water there and a sight glass.

 

[MEP001]

Most boiler expansion tanks are not bladder tanks but just steel expansion tanks at a high point with the make-up water there and a sight glass.

You're right - I'm familiar with boilers but not with their use in floor heat systems.

 

[Buzzie8]

You quoted you filled the expansion tank then purged air? Where did you purge the air from, the expansion tank should be only less than half full of liquid and holding the rest full of air.

I purged air by filling expansion tank half way. Shutting all manifolds, and letting air out of top of expansion tank by pumping fluid through each manifold one at a time.

 

[robtl]

When all is said and done with bleeding the system of air and the correct amount of glycol and the operating pressure is is up the expansion tank should be half full of liquid and the top of air so when the water or glycol can have a place to expand to when heated up and not raise the pressure to blow off the relief valve.If the tank is not fill with air then when when the water cools the pressure drops and the automatic fill valve will make up water there diluting the mix over and over until it is in bad shape again.
Some people shut the auto fill valve so this wont happen but you are playing with a dangerous situation that could cause trouble later on.
If everything is right there will be no danger and the system will work for ever,,,
I have a radiant heating system with a boiler in my house with over 5,000 ft of tubing and it has been working for over 30years and all I have spent on the system is one thermocouple replacement, go figure.

 

[DiamondWash]

What about the slab stat was it working properly or do you have one?

 

[dogwasher]

Pictures would be great. Do you have a torpedo like fill tank mounted above the boiler with a sight glass? If so and you see the Glycol in the sight glass then this would not cause the flow switch to cut out. You may have another problem, possibly the pump/impeller not pushing water or you may need to adjust that flow switch(if the flow switch is the problem)