Calorifier With Immersion Element

[kpnut]

Lovely atmospheric photos Sam. 
Good on you for practicing Ludham Bridge again. ‘Diva’ looks snuggly and content. 

Now, I do know what an expansion tank is. I was going to pm you this morning about it, specifically about whether you’d needed one with the new calorifier and if so, it’s capacity. (And capacity of the calorifier in case that makes a difference when comparing the two. I’m going to put in a 40L calorifier, down from the ancient unlagged 60L one there now with no thermostat or immersion). Maybe Graham can tell me. 

And without meaning to hijack your thread, can someone tell me whether I need a single coil or twin coil calorifier? Only running hot water off it, not wet heating, but could I somehow link it to a solar panel in future and so heat up water if not on shore power and not having the engine running? We run our hot water tank at home off the solar panels via a diverter. 
 

Now back to your post-why does being on a boat create so much more washing than the equivalent number of days at home? One of life’s mysteries!

 

Hope your journey home was straightforward. Gloomy day here in E.Yorks, the forecast sun never made an appearance. 

[Lulu]

1 hour ago, kpnut said:

Now, I do know what an expansion tank is. I was going to pm you this morning about it, specifically about whether you’d needed one with the new calorifier and if so, it’s capacity. (And capacity of the calorifier in case that makes a difference when comparing the two. I’m going to put in a 40L calorifier, down from the ancient unlagged 60L one there now with no thermostat or immersion). Maybe Graham can tell me. 

And without meaning to hijack your thread, can someone tell me whether I need a single coil or twin coil calorifier? Only running hot water off it, not wet heating, but could I somehow link it to a solar panel in future and so heat up water if not on shore power and not having the engine running? We run our hot water tank at home off the solar panels via a diverter. 

Ours is a 55 ltr calorifier with a 5 ltr expansion tank

Graham has said -  with a 40 ltr calorifier you can have  a 5 ltr expansion tank.  Just need a single coil.  Also, he recommends a non return valve on the cold water input feed to the calorifier

You can link solar panels to an inverter to power the immersion coil but the cost would probably outweigh the outlay costs of purchasing the solar panel, cabling, inverter, control panel etc of running your engine for half an hour to heat 40ltrs of water. 
 

Graham has said this is purely how he has done it.  I have no clue what he has just told me 😁

[kpnut]

Many thanks Sam and Graham. That’s very useful. I need to make sure I’ve got room for the expansion tank in that case as I don’t think the existing tank has one, or at least I can’t see one. 
I thought about the solar because I already have a panel on the roof, not a particularly big one, maybe 100W, (kW??). It tops up the batteries. There was also a 1800W/max 3kW inverter on board when I bought the boat to run some 240v sockets when not on shore power. I never feel the need to use this, I don’t have a microwave for instance and no room for one. So maybe I could use that? Anyway, just another thought for me to lose sleep over!!

Many thanks. 

[JanetAnne]

Your inverter will run your immersion heater nicely - for about 90seconds! On paper it looks perfectly feasible but, in reality, you'll just hammer the batteries into submission.

I always go for a twin coil calorifier even if the second coil is not going to be used. The price difference is not too much and it does afford flexibility in the future should your onboard systems be changed. 

[kpnut]

So it’s an all round no to solar then! Thanks Graham and Dave. 
I did notice the twin coil was only about £30 more, that’s what got me thinking this morning. 
 

 

[JanetAnne]

11 hours ago, kpnut said:

So it’s an all round no to solar then! Thanks Graham and Dave. 
I did notice the twin coil was only about £30 more, that’s what got me thinking this morning. 
 

 

I have 600w of solar (at12v) on my houseboat charging 4x130ah batteries and it runs everything perfectly including an occasional  toaster. Then again, it has to, no engine and no shore power!

 

[BroadAmbition]

How about going for a lagged tank with immersion heater but no coils? - double skinned water jacket instead. Vetus one (via french marine). Warms up far quicker. We have this set up.

Having two large solar panels and six 120amp leisure batteries, two alternators, we can in theory use the 1kw immersion heater via the inverter but we never do. Immersion heater is only on if plugged into shore power. Works for us

Griff

[Andrewcook]

Hi, Griff as to this Hot water tank installed on Broad Ambition and using Shore power if and when possible as this does save the engine from running and less annoyance to other Boaters moored up. It's a pity these Hiring  Boat yards did not follow what you have accomplished.

[Vaughan]

32 minutes ago, Andrewcook said:

It's a pity these Hiring  Boat yards did not follow what you have accomplished.

I am sure they would if shore power were readily available, which it is not.

[mikeyboy1966]

1 hour ago, Andrewcook said:

Hi, Griff as to this Hot water tank installed on Broad Ambition and using Shore power if and when possible as this does save the engine from running and less annoyance to other Boaters moored up. It's a pity these Hiring  Boat yards did not follow what you have accomplished.

If I’m understanding this correctly,

the hot water is still heated from the engine,

but the tank has a double skin instead of coils ,thus the whole tank is surrounded by engine heated water

[kpnut]

Oops Sam, sorry to diverge. 
I’ll ask Grendel to move the calorifier oats to a new thread. Thanks everyone, very useful information. 

[grendel]

split into a new post as requested

 

[kpnut]

Ooh, speedy work Grendel. Many thanks. 

[BrundallNavy]

We quite often run the immersion via the inverter, but normally when the engine is running.  Our tank will keep the water hot enough overnight to have a shower in the morning but remember the more hot water you take out the more cold water goes in to replace it. We have 600 amps via a 3kw inverter. 

[BroadAmbition]

If I’m understanding this correctly,

Seems you are

the hot water is still heated from the engine,

Yes when running (Whilst underway normally)

but the tank has a double skin instead of coils, thus the whole tank is surrounded by engine heated water

That's correct - Warms up much faster

Griff

[annv]

It all depends on how you use the boat we have a twin coil as we often moor for several days and run the hot water tank coil from our water heater in the absence of shore power saves running engine just to heat the water and with solar to charge the battery's. John

[BroadAmbition]

I am sure they would if shore power were readily available, which it is not.

Even then do most hire boats have a large tank with an immersion fitted 240v wired, shore power plug and lead - Some but not the majority

Griff

[Smoggy]

You could heat the water by solar but not practically by solar electric, solar thermal collectors are heavy and need a lot of plumbing and a controller though and a way of dumping excess heat when the water is up to temperature, doable but not really feasable.

If you go for a twin coil tank you can maybe fit one of the diesel water heaters in the future but not cheap, they are like an eber but heat water instead of air.

[NeilB]

29 minutes ago, Smoggy said:

If you go for a twin coil tank you can maybe fit one of the diesel water heaters in the future but not cheap, they are like an eber but heat water instead of air.

Previous owners fitted a Webasto wet system on my boat, heats water plus 4 x radiators and I love it.  Some boats don't have enough room for radiators though.

I'm sure I saw an invoice for less than £2K, still expensive but less than I thought it would be.

[Smoggy]

Spotted on ebay.

Eber water heater

 

 

[kpnut]

6 hours ago, BrundallNavy said:

We quite often run the immersion via the inverter, but normally when the engine is running.

Why do you do that, does the engine running not heat your hot water?

6 hours ago, BrundallNavy said:

the more hot water you take out the more cold water goes in to replace it

Am I right in my thinking that going down to a 40L tank from 60L will be ok as the engine heats it to about 80 anyway, so I add cold to mix with it at the taps. So therefore not using so much?
Saying that it heats it to that temp already, so I already do the ‘mixing at the taps’,  and with a 60L tank I do run out after a day. 

 

10 hours ago, BroadAmbition said:

How about going for a lagged tank with immersion heater but no coils? - double skinned water jacket instead. Vetus one (via french marine). Warms

Thanks Griff, I hadn’t heard of that before, so now another evening of research ahead! 
I think I’ll give up on the inverter idea though, you and Dave and others have convinced me my lowly set up is not beefy enough and there’s not really room for more batteries, more solar panels etc. 

 

6 hours ago, annv said:

we have a twin coil as we often moor for several days and run the hot water tank coil from our water heater in the absence of shore power saves running engine just to heat the water and with solar to charge the battery's

I hate running the engjne on idle just to heat up water, so if going nowhere, I just don’t have hot water!
Im not sure i understand this. What is the ‘water heater’ you describe? I only have the one hot water tank that can get hot from the engine (and from shore power once I have an immersion heater element added).  
Do you have a ‘wet’ radiator system that heats up from something like a webasto heater? I’ve read that canal boats often have a normal domestic heating setup, so I presume a webasto or similar sort of acts like a boiler, heating the water in the central heating pipes. So, if so, does that heat also heat up the water in the calorifier when the radiators are on?

 

6 hours ago, Smoggy said:

If you go for a twin coil tank you can maybe fit one of the diesel water heaters in the future but not cheap, they are like an eber but heat water instead of air.

I think that’s answered that query then, thanks Smoggy. 
 

 

6 hours ago, NeilB said:

Previous owners fitted a Webasto wet system on my boat, heats water plus 4 x radiators and I love it.  Some boats don't have enough room for radiators though.

And you’ve just confirmed it Neil, thanks. And how luxurious does that sound? How lovely. 
My boat definitely has no room for radiators. Wouldn’t it be lovely to have a warm towel rail in the bathroom, dream on!

Well thanks to all of you, I’ve learnt an awful lot about this. 

 

 

 

[rightsaidfred]

1 hour ago, kpnut said:

Im not sure i understand this. What is the ‘water heater’ you describe? I only have the one hot water tank that can get hot from the engine (and from shore power once I have an immersion heater element added).  

Do you have a ‘wet’ radiator system that heats up from something like a webasto heater? I’ve read that canal boats often have a normal domestic heating setup, so I presume a webasto or similar sort of acts like a boiler, heating the water in the central heating pipes. So, if so, does that heat also heat up the water in the calorifier when the radiators are on?

 

I think that’s answered that query then, thanks Smoggy. 
 

 

And you’ve just confirmed it Neil, thanks. And how luxurious does that sound? How lovely. 
My boat definitely has no room for radiators. Wouldn’t it be lovely to have a warm towel rail in the bathroom, dream on!

Well thanks to all of you, I’ve learnt an awful lot about this. 

 

 

 

The Webasto system you are referring to has either radiators or hot air heating and also heats the water not cheap but gives you options, if your interested talk to Tom at JPC.

Fred

[Smoggy]

Why not get yourself a small genny, anything over a kw should do it and be much quieter and less invasive than running a boat engine, I did just that at southwold this year as were on a private pontoon with no power for 3 days, my old £50 genny did a grand job and topped the batteries via the charger at the same time although slightly overloaded, I don't suppose modern inverter type gennys would cope with the overload as well but mine is an old school job with no real electronics.

[grendel]

the old style genny, when overloaded would have adjusted the frequency to enable it to cope with the overload, for most equipment this wouldnt have been a major problem.

[annv]

Hi Kpnut My water heater/boiler heats the second coil to give hot water or can also heat the boat as well,  second coil is heated by engine,   also engine heat can be used to heat the boat when engine is running, saves on fuel by switching water heater of when cruising in winter by using engine heat then when moored we switch heater on to heat boat. John