Water heater for yacht with direct cooled engine

[rotrax]

There are plenty of gas hot water heaters available, provided ventilation is good they should be no more potentialy dangerous than a cooker.

The boat we purchased recently in NZ has one to the side of the galley. It has a heat shield above the outlet vent-it produces plenty of heat there-and heats the water up quite quickly.

Ventilation is not a problem as it is within 1 metre of the hatch. If the shower is used the hatch must be open, but for washing up the 20 or 30 seconds it takes to fill the bowl is not a problem.

You know a Vaillant type works-fit another. I am sure you can find an alternative site for one. Very common on Narrowboats. IIRC the Paloma on a Narrowboat we owned in the 70's had a flue.

Good Luck!

 

[toad]

The easiest way would be to replace the heater with a Hydronic Eberspacher (other makes are available) and a calorifier.
I have one, 5 Kw, with a 20 litre calorifier and that's enough hot water for most uses. The hot water also goes through a matrix to provide blown

+1 with the up side of hot water anytime or go the hole hog and get a twin coil calorifier.

 

[vyv_cox]

There are plenty of gas hot water heaters available, provided ventilation is good they should be no more potentialy dangerous than a cooker.

Many surveyors suffer a knee-jerk reaction when they see one, condemning it without consideration. We had one on our GK29, installed by a previous owner it had been there for years without a problem. The burner and unflued exhaust were totally open to atmosphere, making it virtually impossible to produce CO. The overall effect was no more dangerous than cooking on the stove. The man who bought the boat from me had it surveyed several years later for insurance reasons, upon which the surveyor nearly had a fit, issuing severe warnings against its continued use. Of course, the insurance company supported him and the owner was forced to remove it.

 

[rotrax]

Many surveyors suffer a knee-jerk reaction when they see one, condemning it without consideration. We had one on our GK29, installed by a previous owner it had been there for years without a problem. The burner and unflued exhaust were totally open to atmosphere, making it virtually impossible to produce CO. The overall effect was no more dangerous than cooking on the stove. The man who bought the boat from me had it surveyed several years later for insurance reasons, upon which the surveyor nearly had a fit, issuing severe warnings against its continued use. Of course, the insurance company supported him and the owner was forced to remove it.

Interesting-many, many canal boats use them and they are subject to regular Boat Safety Certificate inspections.

Perhaps a more enlightened surveyor should be sought.

As I stated in my previous post, our NZ boat has one and plenty of ads for boats there state "Califont"-a local name for instant gas water heaters-as standard equipment.

The one on Ella is a modern Taiwanese one-a Sakura IIRC- and has safety cut outs if there is O2 depletion,poor water or gas flow as well as a flame failure device.

Whats not to like?

 

[chrishelen]

I have a deck saloon ketch, with a Volvo MD22 59hp. I got a heater matrix from a Transit van at the scrappies for a tenner, A 3" duct fan (IIRC £teens). It works a treat. After all, every car has a heater, why not a boat?

That's what I have in mind...did it have any effect on the engine running temp in the winter? I have a feeling the heater would take most of the heat out of the engine.

 

[NormanS]

That's what I have in mind...did it have any effect on the engine running temp in the winter? I have a feeling the heater would take most of the heat out of the engine.

I plumbed the heater matrix into the hot flow to the calorifier. It has no effect on the engine running temperature, which is determined by the engine thermostat. It does probably slightly reduce the domestic water temperature, supplied by the calorifier. For that reason, I tend to switch off the fan, ten minutes or so before stopping the engine, so that the calorifier is as hot as pos.

Sorry about the thread drift, - the original question was about direct cooled engines. When I had one of them, in a mobo, I plumbed hot water from the engine through a standard radiator in the wheelhouse. It was never a great success.

 

[vyv_cox]

That's what I have in mind...did it have any effect on the engine running temp in the winter? I have a feeling the heater would take most of the heat out of the engine.

It is said that a small single cylinder engine may not generate sufficient heat to run a calorifier. Although apparently it will work, a reduction in coolant temperature may cause accelerated wear in the engine. Most multi-cylinder engines will cope well, e.g. there are many Bukh 20 engines running calorifiers.

 

[johnphilip]

Go Indirect

The previous owner of our last boat, a Fulmar, had fitted indirect cooling via a heat exchanger and added a calorifier to the Bukh 20. All worked well. The heat exchanger was a bit of a monster as it had to work with the lower flow rate of seawater that came from the seawater pump than you get on a system designed to cool a heat exchanger. The fresh water circulation through the engine, calorifier and heat exchanger was run by a small 12 volt Jabsco pump.
When we came to sell the new owner was suspicious of the modification and had a marine engineer come out for an engine test but he gave it a clean bill of health. Additional benefit is that the engine is now only having clean coolant run through it.