New Hydronic – Turtle

Nothing is ever easy…

We spent Wednesday and Saturday swapping out the old hydronic unit with a new one from ITR. The job took way longer than anticipated for a number of reasons. There were small issues (broken fasteners on the old install, changes to the hose locations and sizes on the new heater, a failed external DC pump) and large ones (a bad relay on the new unit preventing ground on the circulation pump). But, by Saturday afternoon we had heat.

The basic sequence was.

Shut down DC power at the laz breaker, shut down AC power at the panel.
Close all the valves to the coolant lines. This took a little planning, since we wanted to drain the coolant from the heater itself, but not from all of the lines throughout the boat. This turned out to be a challenge, since there were no valves to the engine loop. Clamp lines without valves.
Disconnect the primary “out” coolant line from the heater (there was a small amount of coolant to catch here – the bit trapped in the line between the heater and valve). This was the air ingress point for when we drained.
Pump out the coolant from access valve in the bottom of the heater. This went into a 5 gallon bucket for disposal.
Disconnect remaining coolant hoses.
Shut off domestic water valves and disconnect (i.e. cut) pex pipe.
Shut of diesel valves and disconnect diesel lines.
Disconnect electrical.
Disconnect air intake and exhaust.
Remove mounting hardware.
Get two middle-aged guys to lift an 85 pound heater out of a 3’ tall engine room. (Hilarity ensued.)
Install new heater and connect all fittings. It was here where we ran into trouble with different sized hose barbs, a misaligned hole for the exhaust, and a dead circulation pump. We spoke with ITR tech support and scavenged parts from the old heater.
Pump new coolant into system, allowing air to escape through engine reservoir tank and hydronic overflow bottle.
Bleed air from system at all bleeder screws.
Fire up burner and let warm up.
Fire up AC elements and verify functionality.
Run main engine until warm, then top up reservoir tank.

I am glossing over a lot. There were several little challenges that involved running to Longship or Home Depot. When the circulation pump failed to start it was 9 pm, and we gave up for the evening. But, we started in again on Saturday and now Turtle has heat.

Job Notes

The old hydronic boiler had 1,545.2 hours on it when we pulled it. This is over triple the hours on the main (~400), 15 times what we have on the generator (~100) and 30x what we have on the water maker (~50). By that measure, it’s by far our heaviest-used piece of equipment.
The coolant in the hydronic mixes directly with the coolant in the main engine. For some reason, I thought this was separated either in the hydronic heat exchanger or on the engine heat exchanger. But, it’s pretty clear from tracing the tubing and consulting the documentation that it is not. This means that, even though we used the non-toxic propylene glycol for the hydronic (in case it adulterates the domestic water), it mixed with whatever they put into the main engine when the boat came from China. It also means that when the coolant was being consumed in the old boiler, there was a risk of it pulling from the main engine.
We were not able to get the main engine hot enough to open the thermostat when sitting at the dock, so there may still be air in the lines. I will need to test this under load.
The old sound insulation was disintegrating and leaving particles all over the engine room. There was only some very thin foam under the old unit that had become soaked with coolant. We replaced the pad with some heavy-weight material and that alone reduced noise considerably. I will replace the foam material with something more suitable. The problem seems to be mostly resonance and less the thickness of the wall.
We added valves to the engine loop so it can be turned off at the heater. Because of the placement on the top of the unit, we had to add a U-shaped assembly which is heavy enough to bend the lines. So, we added support for these. Now, coolant flow can be turned off both at the heater and at the engine.
The engine loop includes the hydronic heater and the domestic water heater in series.
I was not mixing the coolant 50/50 with water when topping up the system. Un-diluted concentrated antifreeze does not work as well. All new coolant was mixed 50/50.

Viking Marine

I worked with BJ from Viking Marine on this job. He’s methodical, persistent, patient, and conscientious. So, of course he’s booked out until next winter. He not only stuck out completing the job when it went way beyond anticipated scope (we were hoping for a half-day), he let me help and taught me stuff along the way. Getting hands-on experience with a technician is extremely valuable, and I’m always grateful when they take the time to explain things. In addition to the hydronic job, he did a mini-survey of sorts, helping me identify and address a handful of small issues. If you’re near Poulsbo and can get on his schedule, I highly recommend him.

Follow up items

Order and install sound insulation along forward end of fuel tank and along the hull behind the heater. There is already sound insulation along the forward engine room bulkhead, so more there will likely not do much.
I flipped to the backup secondary fuel filter, which I have not changed since the boat was new (there was still non-dyed fuel in there. Fun fact – the pink dye in diesel indicates it hasn’t been taxed for roads. If it’s pale yellow, it’s been taxed (i.e. is from a land fuel station instead of a marine fuel dock). To-do: change the old fuel filter (use the “from” fuel valve from the tank to top up the filter reservoir).
The case ground added to the inverter/charger by Emerald Harbor Marine was not installed correctly. It was attached on top of paint and was rattling loose on the case. Viking showed me how to attach it correctly to the case ground bolt by flipping it upside down. To-do: fix case ground – remember to disconnect DC, shut off inverter-charger, and completely disconnect shore power. DC can be disconnected from the relay in the panel in the laz as well as from the toggle in the pilothouse. Note that the pilothouse toggle needs to be reset when reconnecting (it will flash).
The new ELCI breaker has still not tripped – even during some very cold nights. However, Viking suspects that the temperature sensitivity is likely somewhere else on the boat and not in the hydraulic-electrical breaker. There’s some wiring somewhere that is causing the imbalance. Monitor.
Viking inspected Turtle’s gelcoat. He thinks the discoloration is a dye issue and not thinness or anything structural. Unfortunately, there’s really no <$150,000 way to fix it. It’s basically remove all of the external hardware and apply a layer of gelcoat or paint on the entire boat. The good news is it’s structurally ok (it’s not going to crack). In related news, he thinks the cracks between the cockpit and superstructure are normal and I should ignore them.
Viking walked me through tightening the engine mounts, which there’s no way to do without verifying shaft alignment. While I have monkeyed with this on my old boat, I would still want help the first time I attempt this. So, this is something to book a mechanic for.
There’s something under the generator – it looks like salt (from dried sea water) in some yellowish fluid. There’s nothing in the generator pan. WTF?
It looks like there is coolant leaking from the domestic hot water heater case. This suggests it’s corroding underneath that fancy stainless steel case. Viking recommended just ripping the whole thing out since it’s an expensive, fault-prone backup to the hydronic. I’m inclined to agree.