My Aqua Hot boiler tank sprung a leak

[96 EVO]

Well, after 8.5yrs of zero problems, I'm pretty sure my tank has split 😞!

Think the boiler fluid is getting right into the combustion chamber, as it's blowing sweet smelling exhaust! Leaking out around the exhaust pipe when it get's up to temperature.

Wish me luck! 

[timaz996]

I do wish you luck.

[Ivan K]

I had it leaking around the exhaust, not through the exhaust, that sucks, sorry...

[Frank Bergamo]

Check around the filler neck. Sometimes the whole filler neck detaches from the boiler, leaking down around the boiler. While you are at, check the line to the surge tank, it can also leak at the filler neck. Hope it’s that simple!

[96 EVO]

Wish that was it Frank.

The burner would run fine without excess smoke.

[On_the_road]

When it is cold, you could pressurize it with air the way the manual describes for bleeding the air out.   If you had a leak, this would force liquid coolant out the exhaust pipe.   Or, you could pull the burner out and look in the firebox, a leak should be evident.   Otherwise, it does not sound good.

[Paul Busch]

Mine is leaking when around the pressure cap when it comes up to temperature. It doesn’t smoke or is in the combustion chamber but runs over the top and down through the the air intake. The expansion tank haven’t moved in a year and I have to add about a gallon of boiler fluid every several weeks. My weekend project is to de-solder the boiler cap and install a no-solder neck from Rodger Berk in Florida. 250 but cheaper than pulling the boiler out to work on it. 
 

Did your boiler freeze or did you see boiler fluid in the combustion chamber?

If it is only leaking when coming up to temperature I would test the pressure  cap to make sure it is working then check the tank pressure. If your reservoir tank is not fluctuating during operation then it could be the same issues I have.

[96 EVO]

3 hours ago, Paul Busch said:

 
 

Did your boiler freeze or did you see boiler fluid in the combustion chamber?

If it is only leaking when coming up to temperature I would test the pressure  cap to make sure it is working then check the tank pressure. If your reservoir tank is not fluctuating during operation then it could be the same issues I have.

Expansion tank emptied, and fluid in the boiler tank escaped enough to shut unit down with low level fault. 

I topped it up and ran it, watching the cap area. When it got up to temp I could see it running out at the exhaust.

I'll pull the burner when the weather improves, and check inside the exhaust exit for boiler fluid. I'm expecting to find some.

Oh, tested the leaked fluid and it's good to -34 Celsius. Coldest it has been is -6c

Edited December 9, 2022 by 96 EVO

[Paul Busch]

GOOD LUCK

[Ivan K]

I had a pinhole at the bottom outside of exhaust port, not in the burner tube. Before tearing it apart, I tried boiler fluid sealant and it stopped the leak, probably 6 years going now. That may or may not be worth a try since yours appears to be in the high heat area and sounds more than just a drip. Could be a last resort before taking it out.

[96 EVO]

19 minutes ago, Ivan K said:

I had a pinhole at the bottom outside of exhaust port, not in the burner tube. Before tearing it apart, I tried boiler fluid sealant and it stopped the leak, probably 6 years going now. That may or may not be worth a try since yours appears to be in the high heat area and sounds more than just a drip. Could be a last resort before taking it out.

I'll try heating just with the electric element today. If that doesn't build enough pressure to start it leaking, I'll consider trying a stop leak.

[Ivan K]

3 minutes ago, 96 EVO said:

I'll try heating just with the electric element today. If that doesn't build enough pressure to start it leaking, I'll consider trying a stop leak.

That's exactly what I did since I had the unit out and could only run electric to find the leak source. Good luck!

[96 EVO]

Pretty steady drip coming out of it after only about 15min on electric. Must be a decent size crack.

[96 EVO]

Doesn't appear to be leaking into the combustion chamber. Think the sweet smell was coming from the antifreeze burning off the hot exhaust elbow, then the fumes being sucked into the burner intake fan.

I had installed a piece of window screen over the  intake opening to keep critters out, and it was soaked with coolant.

No further ahead, but makes repair a possibility!

[Guest Ray Davis]

Dr4Film  used a stop leak call Iron Tight, I think.  He swears by it.  

Edited December 15, 2022 by Ray Davis

[Dr4Film]

Unless you intend on removing the Aqua-Hot unit to rebuild it yourself which will save you tons of money, my suggestion would be to scrap the POS and install an Espar Mobile Comfort Model 16 unit which is more powerful than any of the Aqua-Hot units. The overall size is smaller, 5-gallon boiler tank, easier to service yourself and has hot water on demand. There are many more advantages to the Espar unit versus being stuck with another failure prone Aqua-Hot unit.

Here is the link to where my friend had his installed.

Rixen’s Enterprises, Inc. | MCS16 Furnace System Complete (rixens.com)

[96 EVO]

Too funny!

Been discussing just that unit on IRV. If worst comes to worst, I would retrofit that unit in before I'd buy a new AH!

4000W of electric elements is very appealing!

Have you ever heard your friends run? How does it compare to the hi-pitched whine of the Webasto burners?

Edited December 15, 2022 by 96 EVO

[96 EVO]

I won't put down the AH units cause mine has been trouble free for the 9yrs I've owned the coach.

Unfortunately, it's gone from hero to zero in a millisecond 😢!

[Chargerman]

Considering how many Aquahots are out there and how few the problems are in proportion I think it’s a stretch to call them a P.O.S.  In 8 years I have had one problem. The electric eye failed. An easy fix. I just followed the manufacturer’s details troubleshooting guide. 

Not knocking the Rixen unit at all but what’s to say it’s better?  

[96 EVO]

16 minutes ago, Chargerman said:

Considering how many Aquahots are out there and how few the problems are in proportion I think it’s a stretch to call them a P.O.S.  In 8 years I have had one problem. The electric eye failed. An easy fix. I just followed the manufacturer’s details troubleshooting guide. 

Not knocking the Rixen unit at all but what’s to say it’s better?  

Did your Executive come with the 600 series AH?

If so, there's a big difference in the heat output of a 600 and a 450 series unit.

[Paul Busch]

I lost fluid from my boiler and it ran down over the exhaust. It was from a cracked plastic fitting on the front bottom of the boiler. Replaced it with a new brass one. Good luck.

[96 EVO]

3 minutes ago, Paul Busch said:

I lost fluid from my boiler and it ran down over the exhaust. It was from a cracked plastic fitting on the front bottom of the boiler. Replaced it with a new brass one. Good luck.

Thanks!

I've checked that, and my unit came with brass drain fitting ( it's dry). I think I've gotten a decent look at all fittings, and they all look/ feel dry.

[Paul Busch]

Great

[96 EVO]

23 minutes ago, Paul Busch said:

Great

Not really!

I would be popping the Champaign cork if that was all it was 😁! 

[Dr4Film]

13 hours ago, Chargerman said:

Considering how many Aquahots are out there and how few the problems are in proportion I think it’s a stretch to call them a P.O.S.  In 8 years I have had one problem. The electric eye failed. An easy fix. I just followed the manufacturer’s details troubleshooting guide. 

Not knocking the Rixen unit at all but what’s to say it’s better?  

Maybe the term POS was a bit harsh but from my experience with having two Aqua-Hot systems in my 2002 Windsor, it has not been a blissful experience.

Having the original AH (model 100-01) fail within 4 years of being in service is a bit too much to expect I guess, don't you think! Then, because Monaco decided it needed to be installed in the MIDDLE of the coach instead of near the opening of a bay door, there was no way I was able to do my own service or repairs. I did perform some repairs, but it was always having to contort my body into all sorts of positions just to get the job done. Then there is the exorbitant high cost of control boxes and mine required many. It seemed like I was having to buy a control box every year when service was performed @ just under $1000 each. I could go on and on about how much money I had spent on replacing, repairing and servicing the Aqua-Hot units in my Windsor. That single individual component of my Windsor was by far the BIGGEST nemesis of owning the coach for 18+ years. The replacement Aqua-Hot that was installed back in 2005 is model 431/12 which is basically the same as the 100-01 model that failed.

The 06 Dynasty I now own has an Aqua-Hot model 100-04 and so far, it has been very reliable. However, if one day it decides to FAIL completely, well, trust me I won't be installing another rebuilt Aqua-Hot which nowadays has to be close to or even MORE than the price of a NEW Espar Comfort 16 Hydronic System.

Edited December 16, 2022 by Dr4Film