domestic boilers ie lpg combi boilers

[jayjayranger]

hello everyone this my first posting and here goes pros and con of having a combi boiler on board. and how long will 2 19kg lpg bottles last. ps a little about me im planning and dreaming of fitting out a 60 foot by 12 sailaway. massive project there are many more questions to ask but as that chinaman said about the first step and this is it

[nb maggie]

Don't know how long the gas would last, with a combi it would depend on how much heating you use and how much hot water you use, but I understand (from research as I am about to fit one to my house) that a modern condensing combi is about 95% efficient. While a traditional boiler and storage tank is 70% efficient max.

 

Given that a modern domestic combi costs considerably less than an Alde or similar this could be considered an option in theory. Down side is that they are bigger, but you don't need the calorifier. You also need 240v mains to run combi boliers for the flue fan, electronic controls etc. I don't know if there are any BSC issues about using a domestic bolier, but I would susupect that is its a good installation there should not be, in theory. If I can under building regs install a bolier in an airinfg cupboard off my bedroom, you should be able to install them on a boat safely.

 

But again you would need to check BSC and maybee RCD regs. Nice idea though.

[len]

hello everyone this my first posting and here goes pros and con of having a combi boiler on board. and how long will 2 19kg lpg bottles last. ps a little about me im planning and dreaming of fitting out a 60 foot by 12 sailaway. massive project there are many more questions to ask but as that chinaman said about the first step and this is it

 

Hi there,

 

well we've a combi boiler in the house and they're brill while they are working - but you can be left without heat and hot water when they pack up! So do build in a plan B

 

They can also be prone to problems if water pressure falls below a certain limit, heating the water relies water flow, so you may need to check on that, how viable is a pumped feed? - as for how much LPG gas they use, I'd suggest contacting a seller or manufacturer direct.

 

Another thought is they all require an electricity supply, is there one that will operate on 12v or will you have to provide 240v for the circulating pump?

 

I know the Alde boiler we had could be switched to heat radiators and/or keep the caliorifier[sp] heated up.

Alde do do a combi heater, http://www.alde.co.uk/old/alde3000.htm but it looks more like it's aimed at the motor home market.

 

It's certainly an interesting idea, and there do appear to be a lot of LPG Combi options out there so good luck with the search and let us know the results.

 

Len

[elessina]

hello everyone this my first posting and here goes pros and con of having a combi boiler on board. and how long will 2 19kg lpg bottles last. ps a little about me im planning and dreaming of fitting out a 60 foot by 12 sailaway. massive project there are many more questions to ask but as that chinaman said about the first step and this is it

 

You would have to make sure it had a sealed balance flue, one that sucked fresh air from outside and not inside the boat (to meet BSS regs).

 

If you intend living aboard, I think you would find changing over the gas bottles a pain during winter, as during cold spells you could be using a bottle a week..... depending on how long it is on for.

 

Have you considered a domestic oil (diesel) Combi / pressure jet boiler. Many large barges have these on board. We have a 60ft x 12'-6" barge, but could not find room for a domestic size boiler. If we had the room I would have installed a domestic (oil) boiler.

 

Ian

DB Elessina

[DHutch]

You also need 240v mains to run combi boliers for the flue fan, electronic controls etc.

And they might draw quite a bit of juice too!

 

 

They can also be prone to problems if water pressure falls below a certain limit, heating the water relies water flow, so you may need to check on that, how viable is a pumped feed?

Might also be a problem there, you may need somthing more than the normal Surflo pump to keep it happy.

[jollyroger]

If it's any help, they are fitted in static caravans

[jayjayranger]

well im going to be pumped by the new jabsco vdo diaphram pump as seen at exel boat show carnt remember the model number but what a pump, it has gold bits on it , well it should have for 350 quid the boiler in mind is a valiant turbomax condencer .the reason why not oil is the amount of systems on board .

[Alastair]

well im going to be pumped by the new jabsco vdo diaphram pump as seen at exel boat show carnt remember the model number but what a pump, it has gold bits on it , well it should have for 350 quid the boiler in mind is a valiant turbomax condencer .the reason why not oil is the amount of systems on board .

 

Sorry, but " . . . the amount of systems on board . . " doesn't make sense to me. You will have a diesel engine, yes? So why not use the same fuel supply?

 

This is possible - there are systems out there that work ok with 35sec - hurricane is one. I have a domestic oil boiler set up to work off 35 sec.

[nb maggie]

As regards balanced flues all new combi boilers will be balanced flue.

 

Electric consumption is tyically 150W and you need 1.3 bar water pressure.

 

Have a look at

 

http://www.tradeplumbing.co.uk/product.asp...mid=22&catid=33

 

378 inc VAT plus 30 quid for the LPG conversion, which is I think about half the cost of an Alde and you would save on a calorifier as well!

 

Must be a catch

 

 

 

You would probably also need to use an accumulator to maintain constant pressure and a high pressure pump may not be a bad idea as a standard Jabsco pump works on a 1.0 - 1.7 range, while the high presure ones are about 1.5 - 2.8 dependimg on model.

[GUMPY]

I can comment on gas use in a widebeam heated by an ALDE.

Just under 2x19kg bottles a week.

I dont have that now even with the DBA deal on gas it was way to expensive.

 

If you decide to go for diesel you could install a second tank and use 28sec and not have to worry about the possible loss of red diesel.

 

J