Diesel Bubble fires and back boiler

[longy]

Hi All

 

I am after a bit of advice again from you if you dont mind. I have a diesel bubble pie pod fire with a back boiler. On the outlet pipe theres a thermostat and I am lead to believe when this hits the set temp the heat exchanger kicks in. I can actually hear this kick in by altering the temp stat myself.

 

My dilemma is when I am running the gravity fed fire this consumes no electricity but when the heat exchanger kicks in is this using battery power or is it in someway like a bi metalic system.

 

To save comments from people who say best advice rip it out and put a muli fuel stove in that isnt happening as I am happy with the fire but need advice re power consumption

 

all advice welcome

 

 

 

 

[MtB]

The sound you hear will be a pump starting, to prevent the back boiler from boiling. 

 

Set it at a high temp, say 80c to minimise the time the pump spends running and guzzling precious electricity.

 

Or better, rip out the rads etc and convert the stove to just a stove.  

[longy]

If I was to set the temp to the highest setting am I not more at risk of the back boiler from boiling 

[longy]

The reason I said heat exchanger is because on the boats paperwork it mention the heat exchanger in the location I can hear it. I have a seperate switch for the central heating p pump unless it has 2 pumps.

[Tracy D'arth]

A heat exchanger does not make a noise unless there is a pump in there. Is the stat on the pipe an electric pipe stat with a wire to it? If so it will be switching a pump.

[longy]

Yes theres an electrical wire going from the thermostat attached to the 22mm cooper pipe at the rear of the fire

[longy]

I have been on touch with the previous owner asking what the situation is regarding the back boiler and his reply was that he has had it turned off due to the continuous clonking on and off especially at night.

 

I have no idea what he means by that but I am slightly worried in case I boil over the back boiler or continously run down my batteries when I eventually go CCing

[Tracy D'arth]

Such are the problems of having a pumped system instead of the correctly piped gravity system.

[mrsmelly]

1 minute ago, Tracy D'arth said:

Such are the problems of having a pumped system instead of the correctly piped gravity system.

and a multi fuel stove 

[MtB]

24 minutes ago, carp-addict said:

If I was to set the temp to the highest setting am I not more at risk of the back boiler from boiling 

 

Yes.

 

 

But that is not what I said to do, is it?!

[Tony Brooks]

17 minutes ago, carp-addict said:

If I was to set the temp to the highest setting am I not more at risk of the back boiler from boiling 

 

No, probably less if the radiators are gravity fed, or do you mean the fuel supply is by gravity.

 

You have to differentiate between heat and temperature. The stove puts a given amount of heat into the back boiler, the temperature this amount of heat produces depends upon how much heat is being taken out of the liquid in the back boiler. The more heat removed the lower the temperature.

 

Now the amount of heat transferred between bodies (so a radiator and the air or the two liquids in a heat exchanger) is proportional to the temperature difference so setting the thermostat higher will make the maximum temperature higher so the heat transfer will be higher. However, as the air around a radiator or the "other" liquid in the heat exchanger get hotter the heat transfer reduces.

 

Most Bubble stoves have a flow control to reduce the fuel flow into the burner and thereby altering the amount of heat the stove produces. Have you tried turning this down to minimum at night?

 

I fear the radiator circulation may not be by gravity and if so the pump is absolutely vital to prevent boiling so unless you are able/willing to convert it to a gravity system I think trying to silence the pump may be the only way. This might involve making the mounting flexible, not mounting it of a large board that can resonate, connect using hose rather than solid pipe,  and making up an acoustic housing.

 

 

[peterboat]

14 minutes ago, carp-addict said:

I have been on touch with the previous owner asking what the situation is regarding the back boiler and his reply was that he has had it turned off due to the continuous clonking on and off especially at night.

 

I have no idea what he means by that but I am slightly worried in case I boil over the back boiler or continously run down my batteries when I eventually go CCing

I had one of these in my boat same system, your power use will depend on the size of the pump. Mine worked very well good reliable heat and currently probably the same running costs as coal. Its cleaner as well. A 300watt solar panel will more than likely provide enough electricity to charge your batteries to run the pump? The choice is yours

[Tony Brooks]

9 minutes ago, MtB said:

 

Yes.

 

 

But that is not what I said to do, is it?!

 

Mike suggested raining the thermostat cut in temperature, not the amount of heat the stove can produce.  It may well need a combination of altering the setting on the regulator and the thermostat.

[longy]

Ok thanks everyone I will give it a go 

 

[David Mack]

2 hours ago, carp-addict said:

continously run down my batteries when I eventually go CCing

If you are really continuously cruising then your engine will be running for a few hours most days and will easily be able to supply the electricity to run the pump. On the other hand, if by CCing you mean mooring up for 14 days then moving the minimum distance you can get away with, then the pump's consumption will be the least of your electrical problems.

[longy]

For me its about understanding what does what as I am new to boating in general I will most likely do a mixture of everything from 1 day to 10 days when we cruise.

 

For example I have on board 1 x shoreline 12v/240v fridge and the same in the freezer. When I an running through the victron invertor and using the tv will the fridge and freezer still be running on 12v or will they switch to mains 240v.

[MtB]

1 hour ago, carp-addict said:

For me its about understanding what does what as I am new to boating in general I will most likely do a mixture of everything from 1 day to 10 days when we cruise.

 

For example I have on board 1 x shoreline 12v/240v fridge and the same in the freezer. When I an running through the victron invertor and using the tv will the fridge and freezer still be running on 12v or will they switch to mains 240v.

 

The electricity consumption of these two appliances together will swamp that of a heating pump. 

 

No they will be running on 12v always, regardless of whether you have the inverter turned ON for the telly. 

 

I strongly suggest you keep asking the questions and get yourself up to speed on battery charging and electricity consumption before you start CCing. Start by reading the battery primer here as many times as it takes to understand it properly.

 

https://www.canalworld.net/forums/index.php?/topic/95003-battery-charging-primer/

 

[Tony Brooks]

1 minute ago, MtB said:

 

The electricity consumption of these two appliances together will swamp that of a heating pump. 

 

No they will be running on 12v always, regardless of whether you have the inverter turned ON for the telly. 

 

Not contradicting you, but I think the answer, until we get more info, is who knows! Shoreline have supplied a power supply box to allow a 12/24V DC fridge to run from 240V AC when available. Not sure about any change over mechanism though. I suspect the OP does not really know what he  has got so anything we say at present is an informed guess.

 

Now, Carp-addict, based on what you have told is so far I would recommend that you read, digest, and understand the battery primer pinned at the top of the maintenance forum. If you do not and CC then I can foresee lots of battery problems and even frequent battery replacement.

[Ex Brummie]

I have a Bubble with back boiler that runs a gravity heating system. I also have a circulator (pump) wired into a pipe stat that I only use when first lighting the fire. Set to 60c, when the boiler gets up to 60c, the pump switches on and moves warm water, switching off when the temperature lowers. I leave it switched on for about 30 - 45 mins, by which time the water is able to sustain its own cycling a lot quicker than if left to do so from scratch.