Espar Hydronic L Help

[Wakadui]

I have an Espar Hydronic L heater on my boat. I would like to check coolant level and fill but over-flow tank has no cold-fill level. And over-flow tank and attached tube to lower main tank is empty (even when hot). Don't want to take cap off of main tank for fear of making a mess if full and pressurized (0.2 bar). Third party installed Espar and separate coolant system. Not sure if circulates through engine. I suspect not given the presence of a main and reservoir coolant tank.

Please help.

[Bash]

Originally Posted by Wakadui

I suspect not given the presence of a main and reservoir coolant tank.

Please help.

It wouldn't make any sense to install a hydronic system and not include a heat exchanger to the engine--especially if it was professionally installed. Trace the lines back and it would be pretty easy to find the heat exchanger.

The fact that you have two coolant tanks only means that you have two coolant tanks. The theory behind this is to heat up enough "coolant" so that the system won't cycle so much. Most of these systems want a minimum amount of liquid flowing through them, and the way to achieve that amount on many boats is to add an extra tank.

My advice is to find the contractor who installed the system, and pay him for an hour's worth of his time to walk you through the system. You really don't want to have a system like that on a cruising boat without knowing where the trap doors are located. For example, is there a bleeding valve, or a winter valve, or....?

[Dockhead]

One small comment to the above -- almost every boat in these waters has an Eberspaecher (Espar) heater, mostly hydronic. I have never seen one with a connection to the engine.

This type of heater on a car (I had one on a Land Rover once) of course will work through the engine cooling circuit. That's because one purpose of having such a heater is to pre-heat the engine in cold weather. And because the vehicle heater is also heated from that circuit.

But boats are different. Hardly any reason to preheat them unless you are in the arctic. And there is no cabin heater usually attached to the engine. Just the calorifier.

The way I have usually seen them connected is with a loop inside the calorifier, a separate loop from the engine one. That and the fan coils and that's it.

[Bash]

Originally Posted by Dockhead

But boats are different. Hardly any reason to preheat them unless you are in the arctic. And there is no cabin heater usually attached to the engine. Just the calorifier.

The reason to run a heat exchanger to the engine is not so much to preheat the engine as it is to use the engine's heat to run the system when motoring. With my system, if I was motoring up the coast in foggy weather I could have the heaters on--not to mention hot water--without having to run the furnace. I think that's done pretty commonly in these parts.

[Dockhead]

Originally Posted by Bash

The reason to run a heat exchanger to the engine is not so much to preheat the engine as it is to use the engine's heat to run the system when motoring. With my system, if I was motoring up the coast in foggy weather I could have the heaters on--not to mention hot water--without having to run the furnace. I think that's done pretty commonly in these parts.

Hmm, I see. That's a clever idea, not implemented here. Does your engine put out enough heat to heat up the whole system? Mine (100 hp Yanmar) does not make enough heat to do much even with the calorifier.

[Wakadui]

I remember being told that the engine pre-heat option was not installed. Will trace the lines back to engine. Coolant lines should be warm if Espar Hydronic L is circulating through the engine.