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Topic: Aquahot shuts down after ignition (Read 1161 times) previous topic - next topic

Aquahot shuts down after ignition

Trying to get aquahot running. Just replaced fuel lines no air that i can see in filter. Starts right up, clean exhaust, runs great for maybe minute or minute and a half then shuts down. Exhaust clean at start and stop. Where do I start?

Re: Aquahot shuts down after ignition

Reply #1 –
Replaced nozzle with spare. Flame sensor was black, cleaned and will ohm test tomorrow. Will also try to clean burn pot tomorrow. Any tips or suggestions to look at while apart. Printed 105 page service manual from internet. Will look over tonight. Any tips or tricks appreciated

Re: Aquahot shuts down after ignition

Reply #2 –
I would suspect a crimped fuel line if it worked before changing the lines. It can be either one of the lines. Been there done that.

Re: Aquahot shuts down after ignition

Reply #3 –
While bunner is out and flame sensor is clean, disconnect it from the harness paying attention that the green wire to the sensor is plugged into a green wire in the harness.  Connect your Ohm meter to each plug and measure the resistance.

In bright light of a flashlight, the resistance should be less than 200 ohms.  The dark, the resistance should be very many meg-ohms or even OL (0pen line).  If it fails either test, replace.

Let know what you find.

And, I agree with Red Tractor

Re: Aquahot shuts down after ignition

Reply #4 –
Is the coolant full to the lip on the main unit?

Re: Aquahot shuts down after ignition

Reply #5 –
Did not work before fuel lines. I fired it up it blew cloud of black smoke ran for minute or so then stopped. Examined fuel lines and dry with lots of cracking. It was final motivation for changing fuel lines. Before starting pulled several gallons fuel from main tank with pump connected to supply line at AH unit. Most air was gone. Dont think lines pinched. Fought that battle many times trying to get fuel tank back in. ROYAL PIA! I think flame sensor was sooted up and couldn't detect burn. Will check ohm tomorrow. Would like to check burn pot not sure how. How is the best way to tighten down back bolt to secure burner. It didn't seem tight enough to me. Almost finger tight. Could it have not been tight enough and burner was sucking air

Re: Aquahot shuts down after ignition

Reply #6 –
"Could it have not been tight enough and burner was sucking air".

 I use 10" extension and yes if not tight enough it will suck air and grey smoke comes out the exhaust. (Ask me how I know). Black smoke is caused by fuel not burning You then need to pull out burner tube and clean out the soot.

Re: Aquahot shuts down after ignition

Reply #7 –
Just be carful to NOT over tighten that nut!

Re: Aquahot shuts down after ignition

Reply #8 –
The torque on that nut is measured in in-pounds.  If you over-tighten, the "J" bolt will break and it is a pain to replace. 

Also make sure you don't catch the wires between the burner and the combustion chamber.  It will blow black smoke into the storage bay and you have to take it apart again.

I was told to leave the stainless cover over the burner area at home.  Apparently there is a lot of heat trapped around the parts, which is not good for the stuff there

Re: Aquahot shuts down after ignition

Reply #9 –
Quote from: stevec22 –
.

I was told to leave the stainless cover over the burner area at home.  Apparently there is a lot of heat trapped around the parts, which is not good for the stuff there

Just curious if Rudy recommends this?  I know if the AH is running that bay gets toasty.

Re: Aquahot shuts down after ignition

Reply #10 –
I have left mine off for the last 2 years per Rudy-- the control box has problems when too much heat
Chris

Re: Aquahot shuts down after ignition

Reply #11 –
Quote from: Chris m lang –
I have left mine off for the last 2 years per Rudy-- the control box has problems when too much heat
Chris
Ive bought a new control box, sounds like I better get mine off!  Those things are expensive!

Re: Aquahot shuts down after ignition

Reply #12 –
Tommy, if you have the new one with the pig tails check with Rudy they might not be heat sensitive as they are solid state no contacts.

Re: Aquahot shuts down after ignition

Reply #13 –
I bought my solid state from Rudy. He told me to remove the cover. It's been at home for two years, now.

Re: Aquahot shuts down after ignition

Reply #14 –
Our cover has been off for over 2 years as well, per Rudy!  Also, just a tip for those of us who had cracking fuel lines, especially to the Aqua Hot.  I cut the bad ends off and secured them back with a hose clamp.  Just the supply line, not the return.  Easy to do and the short lines inside of the box, I just replaced them with new.  Works like a charm now.  Oh, I also installed another Racor filter inside of the AH box to further filter the fuel.  When we had issues with the AH originally, I found the cracked lines, so ran a new line from the supply inside of the bay to the main fuel tank.  Took a clean rag and stuffed it around the hose to allow the AH to work.  When we traveled, I pulled the fuel hose out and installed the cap again.  You gotta do what you gotta do when in freezing temps!  Now, all lines hooked back up and working great!  We will get our fuel lines changed out sometime next year when we get back to civilization.  Being full time has it's perks and issues.

Re: Aquahot shuts down after ignition

Reply #15 –
Quote from: Tommy D –
Just curious if Rudy recommends this?
Yes he does, I've rode with him on many service calls and hear him say it every time. Rudy does not like covers on anything...

Re: Aquahot shuts down after ignition

Reply #16 –
The cover and other pretty panels make things in the basement look finished.  You have to remove and replace to check on anything like fuses.  They do not add to or take away from heater operation.  Plus the heat gets into the compartments away from the control unit making its environment better for an electronic device.

If I want my basement to look good, I close the door.

Re: Aquahot shuts down after ignition

Reply #17 –
I too removed my AH cover per Rudy's recommendation but observe my inverter cooling fans constantly running (even when inverter not being used during the winter). Rudy are AH's burner control unit module "extender pigtails" available such that the AH cover can be installed and the AH module be somehow mounted outside the AH enclosure? I have not traveled during the summer with the AH cover off and the inverter running but think it might get toasty enclosed in the bay when traveling west this summer.  Looking for some expert advice Mr. Rudy when also factoring in the other electronics in the coach bay.

Re: Aquahot shuts down after ignition

Reply #18 –
Feeling pretty stupid. How do I remove burn chamber to clean

Re: Aquahot shuts down after ignition

Reply #19 –
You have to move the burner/ignitor out of the way and it just pulls out

the burner tub is on page 12 and I believe it just pulls out then clean with brake cleaner and wire brush