Tuesday, January 22, 2008

Questions from the Class - Heater

Al Thompson asks in response to It Just Gets Worse: OK, fess up: What brand of heater are you being tortured by? Guess: Espar, or perhaps Webasto.

He's not the first to ask the really important question: What is that heater that's causing so much trouble and how can I avoid ever purchasing one by the same company?

We have a Ebersp├Ącher Hydronic 10* installed by the previous owner. It's a specialty heater mostly used by buses, RV, boats, and trucks -- basically any 12 Volt system. It's a diesel burner with a circulating pump which circulates anti-freeze into each cabin. At the cabin, there is a little radiator with a fan which goes off when it hits a certain temperature.

Now for the first year and half or so, it worked like a charm. The only problem we had was the first time we ran out of fuel and didn't realize it. Very embarrassing to call a mechanic to explain to us that we were complete idiots. Turns out the heater has it's own, dedicated 12 gallon tank of diesel. In the future, we're going to use this as a spare jerry can.

This recent series of breakage is due to air in the water pump. The original highly engineered Germanic beauty of a pump -- also sold to BMW for gorgeous finely tuned and ridiculously expensive cars -- decided that it didn't know how to function without water in the system and promptly self-destructed. The impeller simply melted.

Of course, even enterprising do-it-yourself cruisers can't fix this problem because you can't buy the impeller by itself. No, you can only buy the entire water pump. So we bought a new water pump.

The second pump lasted 48 hours. Not having another $360 to throw at the problem and clearly recognizing now that the impeller was a symptom of the problem rather than the problem itself, we decided to find a less perfectly designed, robust and cheap Ahmayreekcan pump. The new pump has the advantage of being poorly designed, clunky and not pretty at all, costs a mere $170, and is designed to stop gracefully in the absence of water in the system. It also has the stellar advantage that you can purchase each and every part separately from each and every other part.

Let this be a cardinal lesson to cost conscious cruisers. If you can't order the component parts, do not buy the assembled device.

I can also vouch for the fact that it does fail as gracefully as designed. In fact, it has done so repeatedly. What it does now is blow warm lovely air for about 5 minutes and then with a sign and a clank, it stops annoyed with our inability to consistently feed it water.

So then we started doing clever things we should have started with like completely pumping out all the existing coolant and replacing it with fresh. We also installed air bleeders at every bump and turn. Air bubbles in the system are bad news. Air bubbles result in locks of the pump. We also defensively installed resisters because apparently this good ole boy USA pump sucks amps like a vacuum and can potentially burn out the fine, sensitive and delicate brain of the Hydronic.

DrC and the mechanic still think it's air in the system - even though DrC purged the system so it ran nothing but pure water. We would purge it again, but the marina turned off the water this afternoon due to the sub zero temperatures plaguing the city.

Which brings us to tonight wherein we are officially in a Catch 22. We can't get heat until the marina turns on the water to the dock enabling us to flush the bubbles out of the system again. And we can't get water on the dock until the temperature reaches a point where we don't care if the heater works.

And before you ask, we have also discovered to our dismay that despite all math to the contrary, you can not run two 15 amp radiant space heaters on a 30 amp plug. I suppose that's another story.

* Points to Al, BTW, as Espar is the American branch of German Ebersp├Ącher.

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