Fix or replace Hurricane Hydronic Heater

[Vespucci]

I have an older Hurricane Hydronic Heating system on my boat (20 years old, but mostly rebuilt by now) . Nice setup, with engine heat exchanger, hot water heater and three cabin zones. The system works, but it takes me a lot of maintenance to keep it going.

For the last year or so I have been struggling with the heater unit getting exceptionally noisy, like 95 db if I'm within a meter or so of the heater!  I trace this to the combustion air blower, which is a small squirrel cage fan. The Hurricane unit seems to be getting overly hot (like 150F / 70C on the outside surface) which is causing the plastic blower wheel to soften and fall out of round, so after a few cycles it fouls the enclosure and starts to buzz like mad.  I've spent many phone calls with the Hurricane folks, who are great to deal with by the way, but have been unable to resolve the issue (exhaust line was replaced to eliminate any potential blockage, air inlet re-routed to avoid pre-heating etc. etc.).

So with this preamble two questions:

1. Any suggestions on what I might do to keep the heater unit itself from getting too hot?  According to the folks at ITR teh enclosure shouldn't be getting hot at all.

2. I'm starting to contemplate retrofitting something like an espar hydronic burner into the system, ie keeping all my existing cabin fans, hot water heater, circulation pumps etc. but just replacing the actual Hurricane Burner unit with an Espar (or something similar). Seems like it shouldn't be too hard to do - perhaps I'd need to whip up my own controller from an arduino but that's not a show stopper for me.  Any ideas on the adviseability of this?

 

[DDW]

The Hurricane cabinet will get warm to the touch but not 150. You could have a blockage on the intake air, which is used to keep the cabinet cool. It sounds like not enough fresh air is circulating through the system for some reason. In my opinion the Hurricane is a better setup than an Espar or Webasto boiler, normally quieter and with lower temp exhaust. If it came to that, swapping it out really should not be difficult, the circ pumps and heat exchangers are generic and will work with any boiler. 

 

[Veeger]

Per DDW, something is wrong for it to be getting that hot.  I will say that the new Hurricanes have a bit larger heat sink/header tank or whatever so that the return line comes into it rather than just back to the burner.  On my catamaran, the coolant was pretty cool and meant that the burner was running a near constant duty cycle.  One that reservoir heats up, it warms the returning fluid and evens things out a bit.  Of course on the cat, the full loop was probably over 100’ long— so plenty of ‘cooling opportunities’.

I’d replace with an updated model rather than downgrading the system with an Espar or Webasto. (Relatively speaking, as they aren’t all bad... I guess)

 

[Not the fake Quattro]

I have installed dozens of heating system.  Most have been webasto hydronic.  I think they are superior to both Espar and hurricane.  I have an AT 55 in my boat.

How many btu's do you want?  The webasto 2010 is a very reliable workhorse, 45,000 btu's

And don't overlook the condition of the loop, many older systems are poorly laid out and don't flow well.  New fans will likely have 3/4" ports vs 5/8"

 

[DDW]

The water temp or flow in the loop isn't the problem heating up the cabinet. Hurricanes have a fresh air intake that feeds both the burner blower and burner compressor. The incoming cool air goes through the cabinet first to cool it. I have two Hurricane systems, the one on the sailboat has exhaust and intake air running coaxial for a few feet, which heats the incoming fresh air a bit. That cabinet runs noticeably warmer than the one on the powerboat, which sucks cool air from the engine room vent. What happens if you remove the air intake hose from the unit and let it draw ambient from the compartment? There should be pretty high velocity air coming out the exhaust. I think you hav a stoppage somewhere. Far less likely is that somehow the burner is producing way too much heat, or perhaps the aquastat or high limit aquastat is bad. 

 

[Vespucci]

I spent a pile of time on this today.  Moving the air intake hose I could hear the blower speed up, so not a blockage per se but certainly a lot of resistance. I will use the shortest possible hose on the inlet and get a blower pushing air into the compartment housing the hurricane.  Measured temp on the top of the enclosure now 125F but temperature near the blower fan down to about 90F.

thanks for the help and suggestions.

the problem persists, though, that this heater has become incredibly noisy, the noise is coming from the (2 year old) blower which vibrates like crazy because the plastic blower wheel is so out of round and unbalanced.   I think I’m looking for a deal on a simpler system.

 

[accnick]

I spent a pile of time on this today.  Moving the air intake hose I could hear the blower speed up, so not a blockage per se but certainly a lot of resistance. I will use the shortest possible hose on the inlet and get a blower pushing air into the compartment housing the hurricane.  Measured temp on the top of the enclosure now 125F but temperature near the blower fan down to about 90F.

thanks for the help and suggestions.

the problem persists, though, that this heater has become incredibly noisy, the noise is coming from the (2 year old) blower which vibrates like crazy because the plastic blower wheel is so out of round and unbalanced.   I think I’m looking for a deal on a simpler system.

At least on forced-air heaters, the combustion air inlet line and the exhaust line need to be the same length and diameter.