Diesel Fumes in Bedroom from HydroHot

[Guardsman]

It got cold this week in N. VA. We turned the Hydro Hot heat on to supplement our electric space heater.
We began to experience fumes in the rear of the coach.

Inspection the following AM revealed no obvious holes in the exhaust pipe, and the unit having been recently serviced doesn't produce obvious smoke.

Any insight will be welcome.

[2 Stroker]

I would say you need a new pipe.
Then I would get this to help you and others.
https://www.campingworld.com/camco-g...venting-system

2 stroker

[Smitty77]

Assuming rear windows are closed! And what about a roof vent, do you keep one cracked for ventilation? (Perhaps if not windy, the diesel exhaust could work itself up and into an open roof vent(?).).

Have you used the Diesel Burner in the HydroHot for the heating/hot water without problems of fumes in the coach?

Does it smell like burnt diesel, or could it be the smell of diesel fuel? (Perhaps a fuel leak, not enough to make it to the ground for you to see? But assuming after turning off the Diesel Burner, the smell dissipates, it would not be diesel fuel smell caused.

Any other recent work that might have left an entrance point for the fumes into the coach?

And how cold is it? We've had good success with augmenting our 1500W portable heater, with the HydroHot on Electric heating element only. Down to mid 30's, and we're fine with this combo. Below mid 30's, we then kick on the electric floor tile, and that covers us to about 30 degrees, when we'll the turn on the Diesel Burner and in our older Allure (04) both zones of the heating.

Best of luck to you. And of course, until you figure it out - do make sure your carbon monoxide alerts are all in good shape!

Smitty

[sanddan]

Is it exhaust fumes or a diesel smell? I get a faint diesel smell from the Hydro Hot in the bath and bedroom sometimes. No leaks that I can see just the smell in that area. It's stronger in the Hydro Hot bay and the storage bay next to it. Been there since we bought the coach in Feb.

[Smitty77]

A post I make many times, is to remind owner's of coaches that were made pre, or even close, to ULSD fuels replacing Type II fuels - the 'rubber' (Not really 'rubber', bit a mixture.) fuel lines did not react well to USLD diesel fuels. Over a period of time, in some cases less then 12-18 months (Based upon posts.), the fuel lines would develop small porosity like leaks. Most of the fuel lines to the engine, are topically metal tubing. But, fuel lines to Hydro/AqualHot and Generator's, were more often the rubber 1/4" variety. Yes, IMO, mandatory recalls should have been forced to replace rubber diesel fuel lines that did not play well with ULSD. (BUT, nope, not much action on this front...). RV and Boating, diesel leaking caused fires, have been attributed to the break down in fuel lines, and small leaks ignited by hot surfaces being touched by the fuel.

For owners of 2004-2005 and easier coaches, a good preventative maintenance item would be to replace the rubber fuel lines with a newer product, designed to handle ULSD. (I went with Gates Barricade Blue Streak fuel lines, for our Generator and Hydro Hot. But I believe starting in late 2005, early 2006 normal fuel lines supplying NAPA, AutoZone, CHief's, etc. - were all adapted to handle ULSD.

OP. If your are smelling 'diesel fumes' vs 'diesel burned exhaust' (And can not describe it, but the do smell different.). A HydroHot that is consuming fuel, will have a higher probability of leaking fuel, if a line is compromised for whatever reason, then a 'static' not in use fuel line. Very possible for it to leak enough to detect an odor, but possibly not enough leakage/seepage to make it thru all of the compartments to the ground.

OK. Off my sharing of this ULSD at risk older rubber fuel lines. I go out of my way to repeat this whenever I can, because one gent I knew from work before I retired, lost his 2000 coach to a leaking diesel fuel line that fed his generator. Luckily, diesel has a much lower ignition point then say gasoline. But nonetheless, if it hits a hot enough surface for long enough - it will ignite...

And of course. Your smell could easily not be related to a diesel leak, and not trying to be an alarmist in these type posts - just passing on what I believe to be a good safety tip to look at, IF you do not know the history of the maintenance of a 2004-2005 and earlier era coach, as far as rubber fuel lines!

My best to you, and please post what you find to be root cause, as it may help others down the road!
Smitty

[Guardsman]

Thanks to all for your thoughtful responses. My hoses are new, the Hydrohot has been essentially rebuilt. But I do need to get a very close look at the exhaust pipe. As it appears to be the original.



We use two small electric heaters unless we are doing laundry or both taking showers.



Will update when i find something.

[Ssgritton]

The hydro hot will work on electric without the diesel switch on to heat? I use it for quick showers but did not know it worked for heat also?

[Spk64]

I am not aware of any HydroHot having enough capacity on electric to heat the coach. But I could be wrong.
If only 1 AC/electric switch most likely not.

[Terry Jay]

I was told the electric puts out 12,000Btu, the Diesel 50,000Btu. A short shower on electric only. On the thermostat, on Heat, Gas is the hydroHot, Elec is the overhead.

[kLI45]

We have a 2002 Intrigue and have the identical issue -
Folks - was recently told by Oregon Motor Coach it’s not exhaust fumes from hydro hot, nor the fuel lines - if your coach has the original green hoses to convey hot glycol water to each heat exchanger, when they get hot, the smell is the plasticizers from the hose material. The only way to eliminate the odor and it’s not hazardous, is to replace the hoses at $3 - $4/ft. It’s an annoyance but something to get use to - crack open one of the windows helps.

[Smitty77]

Originally Posted by Spk64

I am not aware of any HydroHot having enough capacity on electric to heat the coach. But I could be wrong.
If only 1 AC/electric switch most likely not.

The single element electric in our HHE-500xxx series Hydro Hot is not going to heat your coach in the 30's! But, if we're in the 50's and want to take a chill out of the coach without digging out the portable 1500W Vernado unit we carry, it will run the Zone 1 & Zone 2 enough to keep remove the chill. It does shut down once the heat register's have lowered the boiler fluid heat temperature too much. Then about 10 mins or so later, it detects the boiler fluid is back up high enough to kick back on, and does so. And for sure we don't get away with taking a quick shower at the few times we're also using the heating zones!

Some of the bigger units of AquaHot have Dual Elements, and they seem to do a pretty good of providing more heating capacity for both water usage and heating. I frankly do not know if some of the Hydro Hot units have dual elements.

For sure, for actual heating in cold weather conditions - we use the various steps I mentioned in my earlier post. 46 degrees where we are now, no not too cold, but we keep the coach warm with only the Vernado 1500W unit running. We like cool air for sleeping, so I usually get up for a nature call, and if the inside temps have drop to 58-60, I'll set the Vernado off on the west temperature setting. Then when I get up an open the shades and making coffee, I'll set it to either position 2 or 3 and within 10-15 mins, the coach is more then comfortable. That is exactly how we did things last night. 46 outside when I opened the shades at 6:00AM!

Best to all,
Smitty

[Smitty77]

Originally Posted by kLI45

We have a 2002 Intrigue and have the identical issue -
Folks - was recently told by Oregon Motor Coach it’s not exhaust fumes from hydro hot, nor the fuel lines - if your coach has the original green hoses to convey hot glycol water to each heat exchanger, when they get hot, the smell is the plasticizers from the hose material. The only way to eliminate the odor and it’s not hazardous, is to replace the hoses at $3 - $4/ft. It’s an annoyance but something to get use to - crack open one of the windows helps.

While we don't detect any odor from usage of the HydroHot heating, via Diesel Burner and or Electric Element, I was also told by Tech's at OMC about the mentioned hoses. They explained the the silicon hoses do allow some of the water within the boiler fluid, to escape while heated up. And this was the reason I needed to periodically top off the boiler fluid. Usually once every two-three weeks, but with heavy Diesel Burner usage for very cold weather heating, sometimes once a week.

Except for now(:! On this trip we developed a small leak of boiler fluid from the unit. I went to Roger Berke's HydronicHeating board, and walked thru the inspection steps he suggested. (Our era HHW-500-xxx unit, had nylon fittings and a few threaded bushings (Temperature sensor, tank level float). None of the bushings I could get to seemed to be the source of the leakage. Suspect, and actually hope, that it is one of the nylon/plastic elbows coming off the rear of the unit, that I can't get to without removing the unit from the coach. A possibility I have a cracked solder going on one of the coils tubes. (Which usually can be repaired by a re-soldering/brazing.) Or could be a leaking seam of the actual boiler tank itself. (Though, as I understand it, usually the seam leaks are more dramatic then what we're seeing.) Very good odd's (Fingers crossed!) that it's the plastic elbow fittings.

For the last 5-6 weeks since we detected the leak, we've tried to use Electric only. We turn it on before showers, and then off the rest of the time. Maybe have used Diesel Burner 4 times in this period. The leak is faster when using the Diesel Burner, as i understand it probably because of greater heat and thus pressure on the Boiler Fluid in the system. With our limited Electric Element usage, I've only had to top off the fluid 3 times in this 5-6 weeks. We go into the shop next week for our annual repair, and diagnosing the HydroHot is one of our key items on our punch list!

Best to all,
Smitty

[dons2346]

Unless the '02 Intrigue has had a new/different unit installed, it is a Hurricane and it uses engine coolant as a heat transfer median.



I have the Hurricane and in the beginning, the unit stunk. It quit smelling after a winter of continuous use

[kLI45]

Oh yeah - Hurricane. You are correct. It has the green silicon supply hoses and smell when they get hot. Yes, this rolling lunch box has hydronic heating as well from engine - handy for hot water. Had quote for 7k to replace all hoses - we will deal with the smell.

We purchased this rig last year and going through it.

Recently also had issue with front slide - the sync cylinder was leaking causing racking and required to be replaced - told it couldn’t be rebuilt - took 7 weeks to have a new one fab’d At HWH.