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Spaceball · 12-19-2016, 04:06 PM

Why couldn't it have failed in July?... no it has to fail at 2am when it's -1F outside LOL

I noticed it sounding weird, woke me up. The flame was going out every 10 seconds or so then reigniting (smoking like crazy), and the rpm seemed to be varying a little. At first I though maybe the fuel was starting to gel. Checked and fuel was good, it's a winter mix and I put anti gel in it also on last fill up. Tank is nearly full also.

Electric all looked good also, so I reluctantly tore into it, thought I would just go ahead with an annual service type thing and see if that helped as I keep a spare nozzle on hand. The old nozzle looked petty good, but changed it anyway. The combustion chamber had some soot, cleaned that up good. Checked gap on electrodes, all looked good as new again. Put it back together, nope. Same symptoms remained. Dang it.

So I grabbed a compression tester I had in the toolbox to use as a fueal pressure tester to the nozzle port. It fit perfect. Disconnected the electrodes and turned the diesel burner on. Fuel pressure jumped up to 145 for about 2 seconds then dropped back to almost nothing, and would bounce up and down to 50 or so, whenever it caught some pressure it would slightly drag the motor down. Well that explains everything, bad pump.

New fuel pump coming overnight. Dragged out some space heaters and shut off all zones in the coach hoping the single electric element in the aqua hot will keep up with the basement heat register... it should.

Things never seem to break when it's convenient do they?

Bob&AnnaMari · 12-19-2016, 05:10 PM

Nope. Things always seem to break at the most inopportune time. It is interesting that your compression tester worked on the fuel line. (Mine has a rubber tip on it.)

It was great you were able to get such a positive flaw to hold. I thought it was going to be an intermittent that can drive you crazy trying to figure out what it is. It almost sounded like a bad controller. Be glad it was not. Fuel pumps are a lot cheaper than those dang controllers.

I also have to applaud you for getting out in -1 temps. I am such a wienie that I would not even get out in 40 degree weather in Canada when our unit refused to work. I waited until it warmed up to 60.

And as I am sure you learned, space heaters really don't do that much when temps really plummet. Tomorrow will be a better day.

Spaceball · 12-19-2016, 05:50 PM

Quote:

Originally Posted by Bob&AnnaMari

Nope. Things always seem to break at the most inopportune time. It is interesting that your compression tester worked on the fuel line. (Mine has a rubber tip on it.)

It was great you were able to get such a positive flaw to hold. I thought it was going to be an intermittent that can drive you crazy trying to figure out what it is. It almost sounded like a bad controller. Be glad it was not. Fuel pumps are a lot cheaper than those dang controllers.

I also have to applaud you for getting out in -1 temps. I am such a wienie that I would not even get out in 40 degree weather in Canada when our unit refused to work. I waited until it warmed up to 60.

And as I am sure you learned, space heaters really don't do that much when temps really plummet. Tomorrow will be a better day.

Thank you for the kind words. I was more concerned with my pipes freezing up, and after I went outside and seen the smoke cloud it was making... the coach burning down LOL. Maybe my flashlight made it look worse to me, but it sure woke me up further seeing that massive cloud. No going back to sleep at that point, too much adrenaline heh

The compression tester I have is an older one with brass stair stepped sized threads, and an oring on each layer to fit any spark plug hole. The smaller of them fit right into the nozzle. I got lucky on that. I was worried it was going to turn into wild goose chase on the cause. After the annual service work didn't change anything, I turned to the service manual and fuel pressure was the first thing I tested in the toubleshooting section. So I'd say more luck than ability heheh I pray the control board is happy with life, I don't need any more repair expenses this winter

Cheers!

Rburian · 12-19-2016, 06:32 PM

The more I hear about the Aqua heat issues, the more I appreciate the two LP gas furnace and gas/electric WATER heater in my 2005 HR SCEPTER.

adamfolger · 12-19-2016, 06:55 PM

Quote:

Originally Posted by Rjburian

The more I hear about the Aqua heat issues, the more I appreciate the two LP gas furnace and gas/electric WATER heater in my 2005 HR SCEPTER.

Having had both propane and Aquahot I think the down time has been about equal. But the Aquahot advantages are something I don't want to do with out, especially since we are full time. I hated filling two 15 gal tanks and they used up too much space when traveling. AND propane seemed to contribute to humidity build up in the rig. I do carry a portable electrical fire place for emergencies. I have never been in 1* weather. My mind can't go there, so my MH never will.

Kudos to Spaceball for getting out there and doing what had to be done.

Spaceball · 12-19-2016, 07:04 PM

Quote:

Originally Posted by Rjburian

The more I hear about the Aqua heat issues, the more I appreciate the two LP gas furnace and gas/electric WATER heater in my 2005 HR SCEPTER.

I hear yeah, I like both for different reasons. However, my AH is 13 years old now. Prior to this fuel pump issue all it's ever needed was a new radiator cap and annual maintenance. I've had furnaces fail too at inopportune times. Stuff just gets worn out with age unfortunately.

zmotorsports · 12-20-2016, 10:04 AM

Just out of curiosity, grab the fuel filter and make sure it is tight. I had one on a friends coach act very similar a few years ago. The fuel pump is a gear type pump driven off of the blower fan and it was demonstrating a varying fuel pressure reading. It sounded odd to me so I thought it was possibly cavitating. I went to the easiest part first and sure enough the fuel filter was not tight so it was sucking air. My friend had the annual service performed about a month prior and it worked fine until he arrived back here in northern Utah where the temps were lower and the gasket on the filter shrunk back just enough that it started sucking air, hence the varying fuel pressure. I tightened the fuel filter, ran a fuel purge cycle and the system fired and has ran perfectly since.

Just a thought of something to check.

Mike.

Spaceball · 12-20-2016, 04:57 PM

Quote:

Originally Posted by zmotorsports

Just out of curiosity, grab the fuel filter and make sure it is tight. I had one on a friends coach act very similar a few years ago. The fuel pump is a gear type pump driven off of the blower fan and it was demonstrating a varying fuel pressure reading. It sounded odd to me so I thought it was possibly cavitating. I went to the easiest part first and sure enough the fuel filter was not tight so it was sucking air. My friend had the annual service performed about a month prior and it worked fine until he arrived back here in northern Utah where the temps were lower and the gasket on the filter shrunk back just enough that it started sucking air, hence the varying fuel pressure. I tightened the fuel filter, ran a fuel purge cycle and the system fired and has ran perfectly since.

Just a thought of something to check.

Mike.

Thanks Mike, that is a very good suggestion. The filter was pretty tight, and I also went ahead and changed it today when I installed the new pump. I figured since I did all the annual maintenance stuff on the burner I might as well be thorough so everything matches up in my log books heh.

I have heat again! It smokes a little on startup for about a minute but once burning hot it clears up and does not smell. I know many say this is par for the course on these however it's odd that it never smoked at all before the pump failure. The nozzle I put on is a danfoss with the rounded design, the one I took off had the trapezoid style flat top.

Something to fine tune when it's warmer out maybe, I'm just happy to be toasty inside the coach again, I'm ready for a hot shower too ha!

Bob&AnnaMari · 12-20-2016, 05:23 PM

If the smoke is blue to blue-white the burn is a bit fuel starved. If it is black, too rich. At the temps you are experiencing, it would not surprise me that you are seeing some weird things. If it were me, I would wait until I was back to better temps and #2 diesel before I made any judgement.

We use the danfoss nozzles with no problem. (Roger Burke switched to those some time ago and he would not have made the change if there were any issues with that unit.) So, I seriously doubt it is a nozzle issue.

I am still very impressed with all the work you are doing at the temps you are experiencing. You are the man. And thanks for keeping us updated. It is always good to hear how thing work out.

Spaceball · 12-20-2016, 06:35 PM

Thanks for the info. It is blue to blue/white, not very thick either. Makes me wonder how good of shape that spare nozzle was in. It had been rattling around the drawer for some time, in it's plastic case still, but it did have some discoloration. I wonder if it had a tiny bit of corrosion in the orifice. That would certainly make sense if it did, causing a leaner than normal burn.

The nozzle I removed was installed in April of this year so it likely is still good. Supposed to warm up tomorrow, maybe I'll swap it back and see if it clears things up on startup.

Randyman1 · 12-21-2016, 06:45 AM

I know I'm probably gonna get some flack here, but on my coach I use a cetane boost and injector cleaner in every tank of fuel I burn. I use Amsoil products and I haven't experienced any Aqua Hot smoking in over 2 years since it was last serviced. I think some of today's fuels aren't up to snuff and although you don't notice it on the engine, that little injector in the Aqua Hot will show a problem with your fuel quality. Mind you this is my opinion and am not looking to start using additive wars on here. This is what works for me and keeps me burning diesel.

vito.a · 12-21-2016, 10:28 AM

Spaceball, you get my vote for the best cold weather trouble shooting!

becks · 12-21-2016, 11:16 AM

Good work, as stated, especially in cold weather.

Spaceball · 12-21-2016, 12:05 PM

Thanks for the comments.

Just a follow up, It's in the 40s today, T-shirt weather! I swapped the "not so old" nozzle back in and no change. Still smoking at startup, it does clear up after a minute or so. When I had cleaned the combustion chamber it was sooty but not plugged. I wonder if the increased airflow is what's at play. I have a genturi so as not to bother my neighbors, so I may just not worry about it for awhile.

Randy, I do use Howes additive, it's an anti gel/cetane boost. However you sparked a thought that had not occurred to me until just now. It's been a few years since I have been around diesels in that cold of weather. While the fuel itself was not gelled, it's possible that being at the fuel cloud point the paraffins were starting to drop out of solution, and clogged the filter with wax. All I had done at the time was look in the tank and drained some fuel from the filter bowl to see if it was still liquid.

Hindsight is always 20/20 but I'm wondering now if I could have hit that filter with my heat gun and clear up the situation, which also means it's possible I may have purchased a new pump without really needing one.

Fuel quality could be an issue too, which could also have clogged the filter. I wish I would have thought of these things before changing out the pump, but oh well, lesson learned heh

Either way I am going to chalk it up to a remedial vocational course at the University of Hard Knocks.

If we get another cold snap and it happens again, I know what I am going to check. It usually does not get that cold in these parts either, but I think over half the country was saying the same thing last weekend.

The real issue could be that while out having a drink with a buddy a day prior to this issue, I was just bragging about how well things were working in the RV in the cold and I may not have knocked on wood. lol