Heating - stove or central heating?

[blackrose]

6 hours ago, Stilllearning said:

 

I am an agnostic when it comes to galvanic corrosion. The last three boats I lived on did not have them, and all three were moored in marinas and plugged in to shorelines. And had no evidence of corrosion. So you have to decide.

 

 

Are you an agnostic when it comes to gravity and the earth rotating around the sun too?

 

These things are facts. We can debate the effects of galvanic corrosion on steel boats in fresh water and in particular why some boats are affected and others apparently aren't, but the physics itself isn't open to interpretation.

 

https://www.nace.org/resources/general-resources/corrosion-basics/group-1/galvanic-corrosion

 

As far as not having any isolation while the boat is connected to shore power; yes it is a personal choice, but apart from the initial outlay for the unit (be that a galvanic isolator or an islation transformer), I don't really understand what you think the disadvantages are of having an isolator and why anyone wouldn't isolate their boat to mitigate any potential risk?

[The Gravy Boater]

If I were looking at getting heating on a boat that had nothing I would seriously consider a gravity fed diesel stove plumbed to also provide hot water and radiators if needed.  Some people just like burning stuff and a solid fuel stove would be cheaper, but in terms of hassle free and very controllable heating a diesel stove would be ideal in my opinion.

[Keeping Up]

I was on a boat a couple of years ago, that had diesel heating, and was astounded that there was no room thermostat - only a timer. Apparently the system could not even have a thermostat fitted. No way would I have such a system!

[Mike Tee]

You’ve heard the doom and gloom about diesel stoves - now hear our experience.

When living aboard a 60’ trad, we had a Bubble diesel corner stove. Picked the boat up just before Christmas and managed to get down to Milton Keynes, breaking ice for the last day. We were then iced in for over six weeks and had a Mikuni on every morning for one hour to give us a (large) full cauliflower of hot water. The only other heat was the Bubble on 24/7 at its lowest setting, and it ran perfectly with a rolling blue flame - exactly as advertised by the supplier. No black smoke polluting the area, no dramas at all. The only (small) annoyance was shutting it down approx every 6 weeks to clean out the burner - an easy 10 minute job. Chimney was nothing huge but we did have a rotating cowl which helped the draw. 

These days it is more expensive to run than solid fuel, but is much more convenient and I’d have another no problem. Added benefit when the stove was on at its low setting, bring a steamer full of veg up to the boil on the gas cooker, then move it onto the Bubble - similar with jacket spuds in one of those clay pot things.

[Ex Brummie]

6 hours ago, Bee said:

That water cylinder was quite something, the fact that it held over 300 psi is amazing, most steam locos didn't go above 250 psi working pressure .and that is with really hefty plate. Lesson here is to fit an open expansion / header tank or some other suitable pressure relief thingy.

This video has been around the central heating sites for many years, and was produced in America and doctored to produce the bomb. All sealed domestic hot water systems should have a temperature/pressure relief valve, and in a domestic situation would have mains cold water supplying it, which is far in excess of a boat supply. Even then, the relief valve would be routed outside.

[Ex Brummie]

6 hours ago, Tracy D'arth said:

Total agreement with Tony.

 

I have seen more removed than fitted!  Without a long flue extension they do not pull properly. One was so bad it covered a marina in black soot in less than an hour.

There is only one boat i know with an oil burner of this type that works, the guy laced his diesel with kerosine and cleaned it every day, ran it at maximum when lit.

The Bubble I have is one of the best things I fitted on the boat. Mine runs most of the time on the the lowest 2 settings. Yes, the flue needs to be sound, but mine runs quite happily with an outside flue about 2ft high, but I do have a downdraught cowl fitted, and the 4" pipe extends from the collar, and is shrouded within a normal 6" narrowboat chimney. Like any equipment, it needs maintenance, but to have a unit that maintains a steady temperature overnight and does not need rescuing, creates no ash and dust and consumes no battery power, then it is ideal. So there is some uncertainty about the fuel supply and availability, but so is there uncertainty about future legislation about smoke control and the supply of fossil fuels at a realistic price. If my fire is running at 2/5ths, then it consumes 1 litre of fuel every 4 hours. This works out about £4 per day.

[cuthound]

22 hours ago, Tracy D'arth said:

Total agreement with Tony.

 

I have seen more removed than fitted!  Without a long flue extension they do not pull properly. One was so bad it covered a marina in black soot in less than an hour.

There is only one boat i know with an oil burner of this type that works, the guy laced his diesel with kerosine and cleaned it every day, ran it at maximum when lit.

 

I have a Kabola Old Dutch fitted and with the supplied standard length flue.  It works very well and burns with blue flames, as evidenced by the photos in post #47 of this link.

 

 

I also have the shorter "cruising " flue. That flue restricts draught to such an extent that the stove burns yellow on settings 3 and above out of 6. That said setting 2 is more than enough to maintain the boat at 23-25°C. It is our usual winter setting.

 

With oil drip stoves it is essential that the holes in the burner pot are clear and the Toby valve is correctly adjusted. The problem is that there are not many people who can service them, so best to learn to do it yourself. It is easy once you pluck up the courage to try.

 

Once these criteria are met they are excellent stoves, both controllabe and hot, which only require cleaning every 500 hours of running (about 3 weeks of continuous operstion).

Edited June 19, 2020 by cuthound

[blackrose]

22 hours ago, Tracy D'arth said:

In a proper installation the "cylinder" really a calorifier, will have a release valve that operates on both excessive temperature and pressure, its an expensive item.

 

 

How does that differ exactly from an ordinary PRV which costs about a fiver from screwfix?

 

I guess the cheapo valve is only controlled by pressure but I don't understand why you'd need one operated by temperature too?

Edited June 19, 2020 by blackrose

[Tracy D'arth]

17 minutes ago, blackrose said:

 

How does that differ exactly from an ordinary PRV which costs about a fiver from screwfix?

 

I guess the cheapo valve is only controlled by pressure but I don't understand why you'd need one operated by temperature too?

Temperature release is needed because the boiling point under pressure is raised above the boiling point at atmospheric pressure. If the temperature is over 100 degrees C  any escape of water due to a pressure safety valve releasing would instantly flash to steam, very dangerous as the increase in volume is massive.

Its belt and braces really to prevent incidents.

 

 

 

 

[Alan de Enfield]

21 hours ago, Keeping Up said:

I was on a boat a couple of years ago, that had diesel heating, and was astounded that there was no room thermostat - only a timer. Apparently the system could not even have a thermostat fitted. No way would I have such a system!

Presumably that was the owners / installers choice.

 

We have diesel fired heating which is switched on when we get on the boat, and switched off when we leave the boat - it can be 'on' for 5 or 6 months and is controlled by the room thermostat - non of this 'switching it off every 20 minutes to stop I carbonating mularky.

 

 

[booke23]

18 hours ago, Ex Brummie said:

The Bubble I have is one of the best things I fitted on the boat. Mine runs most of the time on the the lowest 2 settings. Yes, the flue needs to be sound, but mine runs quite happily with an outside flue about 2ft high, but I do have a downdraught cowl fitted, and the 4" pipe extends from the collar, and is shrouded within a normal 6" narrowboat chimney. Like any equipment, it needs maintenance, but to have a unit that maintains a steady temperature overnight and does not need rescuing, creates no ash and dust and consumes no battery power, then it is ideal. So there is some uncertainty about the fuel supply and availability, but so is there uncertainty about future legislation about smoke control and the supply of fossil fuels at a realistic price. If my fire is running at 2/5ths, then it consumes 1 litre of fuel every 4 hours. This works out about £4 per day.

If you have a separate tank for the diesel stove, is it possible to run them on home heating oil?

Edited June 19, 2020 by booke23

[Alan de Enfield]

Just now, booke23 said:

If you have a separate tank for the diesel stove, is it possible to run them on home heating oil?

With the correct jets, yes,

 

But where do you get Kero (28 second burning oil) from on the canals ?

[booke23]

Just now, Alan de Enfield said:

With the correct jets, yes,

 

But where do you get Kero (28 second burning oil) from on the canals ?

 

That would be a problem. Unless you had a large enough tank to order minimum delivery (200 litres?) from an oil company.  

 

I was kind of thinking they could run on either Diesel or Kero with no modification, in which case you could just use whatever you could get hold of. I thought I read somewhere that Refleks stoves can run on either Diesel or Kero with no modification. With heating oil currently at 28p/litre the savings would be considerable, but you wouldn't want to modify your stove so you'd have to rely on a heating oil supply. 

 

 

 

 

[Ex Brummie]

20 minutes ago, booke23 said:

If you have a separate tank for the diesel stove, is it possible to run them on home heating oil?

Yes,

 

19 minutes ago, Alan de Enfield said:

With the correct jets, yes,

 

But where do you get Kero (28 second burning oil) from on the canals ?

No jets to replace/modify. There may be a little difference in output allowing for the difference in calorific value of the fuels, but you'd probably not notice any difference.

It is possible to get fuel in portable tubs to fill up a spare tank. from distributors.

2 hours ago, Tracy D'arth said:

Temperature release is needed because the boiling point under pressure is raised above the boiling point at atmospheric pressure. If the temperature is over 100 degrees C  any escape of water due to a pressure safety valve releasing would instantly flash to steam, very dangerous as the increase in volume is massive.

Its belt and braces really to prevent incidents.

 

 

 

 

The combined temperature/pressure relief valves are designed to cope with domestic mains pressure systems and operate at 7 bar.. The pressure relief valves used on boats is only rated at 3 bar. Given that the average pump only givesabout 2 bar, maybe 2.5 bar, then you are very unlikely   never likely to encounter super heated steam as the volume increase will expel before such temperatures are reached.

[Alan de Enfield]

12 minutes ago, booke23 said:

 

That would be a problem. Unless you had a large enough tank to order minimum delivery (200 litres?) from an oil company.  

 

I was kind of thinking they could run on either Diesel or Kero with no modification, in which case you could just use whatever you could get hold of. I thought I read somewhere that Refleks stoves can run on either Diesel or Kero with no modification. With heating oil currently at 28p/litre the savings would be considerable, but you wouldn't want to modify your stove so you'd have to rely on a heating oil supply. 

 

 

 

 

We are on Kero at home - I think the minimum delivery is 250 litres, you would obviously not want to wait until you ran out before you ordered (we normally have a lead time of 5 days  ish), so based on not being exactly correct, or they arrive early I'd suggest that you would need a minimum tank size of 350 litres capacity.

 

I looked at running our home (kero) heating off diesel as we have Red diesel on the farm, as the volumes we buy mean that the price is around the 'small volume' price of kero.

I was told we'd need different jetting. Possibly other manufacturers don't ?

[Ex Brummie]

1 minute ago, Alan de Enfield said:

 

 

I looked at running our home (kero) heating off diesel as we have Red diesel on the farm, as the volumes we buy mean that the price is around the 'small volume' price of kero.

I was told we'd need different jetting. Possibly other manufacturers don't ?

If you are looking at a pressurejet boiler, then yes. You resize the nozzle and increase the pressure. Vaporising / drip feed burners have no jets and operate on gravity feed.

[booke23]

All very interesting. Definitely something to bear in mind if you were building a boat from scratch with a view to having a Diesel stove. Retrofitting a very large gravity feed day tank would be problematic on most narrowboats. 

[Tracy D'arth]

1 hour ago, Ex Brummie said:

Yes,

 

. The pressure relief valves used on boats is only rated at 3 bar. Given that the average pump only givesabout 2 bar, maybe 2.5 bar, then you are very unlikely   never likely to encounter super heated steam as the volume increase will expel before such temperatures are reached.

  Sorry but that's wrong.  at 3 bar the boiling point of water is 133.6 degrees C,  release at that temperature will be 0.606 cubic meters of steam per litre of water, an expansion of over 600 times.

[Tony Brooks]

35 minutes ago, booke23 said:

All very interesting. Definitely something to bear in mind if you were building a boat from scratch with a view to having a Diesel stove. Retrofitting a very large gravity feed day tank would be problematic on most narrowboats. 

As long as you can get it on the rear swim it shoudl not be any problem because the drip feed stoves "carburettor" is only inches above the cabin floor so you will probably have a minimum of 1ft of head.

[ditchcrawler]

1 hour ago, booke23 said:

All very interesting. Definitely something to bear in mind if you were building a boat from scratch with a view to having a Diesel stove. Retrofitting a very large gravity feed day tank would be problematic on most narrowboats. 

It dosent have to be a large gravity feed tank, just a gravity day tank and a pump to top it up.

 

[The Gravy Boater]

36 minutes ago, ditchcrawler said:

It dosent have to be a large gravity feed tank, just a gravity day tank and a pump to top it up.

 

This.  I still think I'm going to end up with a diesel stove.  Just need to sell my exotic solid fuel stove to some sap.

[booke23]

1 hour ago, ditchcrawler said:

It dosent have to be a large gravity feed tank, just a gravity day tank and a pump to top it up.

 

No it absolutely doesn't.

 

I was musing about a large tank so that you could store the minimum delivery quantity of home heating oil to run the diesel stove. At 28p/litre it would make a big difference to your heating bill. However it is absolutely illegal to use heating oil for propulsion, so it would need a separate tank. 

[ditchcrawler]

1 hour ago, booke23 said:

No it absolutely doesn't.

 

I was musing about a large tank so that you could store the minimum delivery quantity of home heating oil to run the diesel stove. At 28p/litre it would make a big difference to your heating bill. However it is absolutely illegal to use heating oil for propulsion, so it would need a separate tank. 

Agreed and if they ever get round to knocking the duty allowance off I shall install another tank somewhere, take heating oil from home. At the moment my day tank is actually a 6 day tank that automatically fills when the engine runs

[Bewildered]

Would a large marine diesel generator run on heating oil?

If so the answer is simple, remove the engine fit a genny in its place and fill the diesel tank with heating oil to run the genny and the heating. This would of course mean that the boat would need to be converted to electric drive but it would get around the problem of not being able to use heating oil for propulsion. As long as the genny is charging batteries and not directly powering the motor this could be the most economical way to cruise. 

Big solar array, big battery bank and genny powered by tax free heating oil; sounds to good to be true, must be a catch somewhere!

[Ex Brummie]

13 hours ago, Tracy D'arth said:

  Sorry but that's wrong.  at 3 bar the boiling point of water is 133.6 degrees C,  release at that temperature will be 0.606 cubic meters of steam per litre of water, an expansion of over 600 times.

You are assuming that there will be no expansion before reaching boiling. With a capacity of less than 1 bar in the system, you would not reach boiling before losing water.