Heating water from the engine (2 Viewers)

[Wildbill]

My water heater is knakerd so thinking of replacing the gas with a heat exchanger.
System a coil in the water heater to use the engine heat from the heater system
Its a bit of tinkering.
To buy a new heater is nearly 500 plus fitting.
I have it all apart at the moment so its only a case of making a coiled loop
And sum tank fitings then plumb in to the system
Mesuerd the pipe run won't be any more than five letters of extra colent
Reckoning abut therty min of driving and a tank full of hot water for nothing
As long as its after the themosstat I suld not affect the working temperature of the engine
Bill

 

[Muddibootz]

I like the thinking. Be interesting to see how you get on.

 

[Flamenca]

I had this system on a boat and it worked efficiently.

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[pappajohn]

It will need to be on the engine side of the stat or it wont get warm enough in cold weather.
What you going to do when on site.....run the engine for an hour ?

 

[Wildbill]

I like the thinking. Be interesting to see how you get on.

Nothing to lose water heater is scrap any way don't she any reason why it should not work.
I have research a bit I might use 10mm pipe yet for the coils
Bill

 

[Wildbill]

It will need to be on the engine side of the stat or it wont get warm enough in cold weather.
What you going to do when on site.....run the engine for an hour ?

I am going to fit a smaller heater I have from my caravan
Bill

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[hchris]

You need to control the flow from the engine a friend has done this and it boils the water in the motorhome heater on a long run.
You need a valve in the feed for the engine that will close when the water heater gets to 60c

 

[Wildbill]

You need to control the flow from the engine a friend has done this and it boils the water in the motorhome heater on a long run.
You need a valve in the feed for the engine that will close when the water heater gets to 60c

Whare do you get the as valves

 

[DBK]

Sounds a good idea Bill, I would take the feed from near the outlet of the pump so there is a better chance of good circulation.

I think you need to fit some sort of safety valve on the hot water tank or perhaps just vent it to atmosphere. The reason is the water from the engine, being pressurised, might be over 100C so the water in the tank could boil. It may never happen but just in case.

Edit: Crossed with @hchris!

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[Wildbill]

I had thought of that think I will fit a solinod valve so it closes at 60dig
Bill

 

[Wildbill]

Sounds a good idea Bill, I would take the feed from near the outlet of the pump so there is a better chance of good circulation.

I think you need to fit some sort of safety valve on the hot water tank or perhaps just vent it to atmosphere. The reason is the water from the engine, being pressurised, might be over 100C so the water in the tank could boil. It may never happen but just in case.

Edit: Crossed with @hchris!

Will put a thermal valve actuator on the down stream side of the system when the water is coming out at 60 deg the water in the boyiler will be the same give or take a few deg
a 12v underfloor heating valve will do the job
Or thermal actuator valve
Bill

 

[chaser]

Here comes my doom and gloom, it all seems to be a lot of trouble just to get some hot water, and only works if the engine is running , must be better to mend what you have, or get a second hand boiler and have it right, just saying

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[Enword]

In the 90s we had an old Merc 407D race van, I made a heat exchanger for the exhaust, just on thermosyphon to a container in the van, worked well but never finished it properly

 

[Enword]

In the 90s we had an old Merc 407D race van, I made a heat exchanger for the exhaust, just on thermosyphon to a container in the van, worked well but never finished it properly

Probably no good for cat/particulate filter type jobbies etc, taking to much heat away from the exhaust.

 

[Wildbill]

Here comes my doom and gloom, it all seems to be a lot of trouble just to get some hot water, and only works if the engine is running , must be better to mend what you have, or get a second hand boiler and have it right, just saying

Whares your since of adventure man seen this work on boats don't she why it won't work on a MH
Bill

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[chaser]

Whares your since of adventure man seen this work on boats don't she why it won't work on a MH
Bill

Quite agree bill my sort of bodge to a t but when you have got to rely on it in the middle of a winter night you won't want to be getting up to go and warm the engine up.

 

[Deleted member 29692]

We've got something similar in our van as part of the Alde heating.

There's a heat exchanger that uses heat from the engine to run the central heating. It doesn't do hot water in ours but the principle has to be the same.

 

[chaser]

Quite agree bill my sort of bodge to a t but when you have got to rely on it in the middle of a winter night you won't want to be getting up to go and warm the engine up.

My son in law had an rv with a similer system but the tank was in the roof so it all worked on gravity , hot from tHe engine went up and down and the hot water system needed no pump as the shower and taps worked on gravity, but it's still a bit iffy in your case where you are going to rely on it every day, not just a weekend.

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[DBK]

We've got something similar in our van as part of the Alde heating.

There's a heat exchanger that uses heat from the engine to run the central heating. It doesn't do hot water in ours but the principle has to be the same.

The Eberspacher heaters are connected to the engine coolant.

 

[Wildbill]

Quite agree bill my sort of bodge to a t but when you have got to rely on it in the middle of a winter night you won't want to be getting up to go and warm the engine up.

I won't be taking a shower in the medal of the night and the blown air heating will keep us toste.
It Hansent worked for three years like I see in the op nothing to lose.
I will be fitting another gas heater but this will save gas free hot water from the engine when we stop
Bill

 

[Deleted member 29692]

The Eberspacher heaters are connected to the engine coolant.

Not familiar with them.

On ours the way I think it works is that there's a heat exchanger where the antifreeze stuff in the Alde central heating meets the engine coolant when the valve is open and heats it. There's a switch on the dash to open and close the valve and it seems to work.

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[Snowbird]

I used a similar system on my Middle East trucks, but piped into the diesel tank to stop the diesel freezing in Bulgaria and Turkey. Worked well and I never had a problem with diesel waxing.

 

[Wildbill]

My son in law had an rv with a similer system but the tank was in the roof so it all worked on gravity , hot from tHe engine went up and down and the hot water system needed no pump as the shower and taps worked on gravity, but it's still a bit iffy in your case where you are going to rely on it every day, not just a weekend.

Folks have had strip washes from a kettil of water for century's
We have managed on sum very extended holidays.
We will be abile to shower when we stop
And ther is always the strip whash option or go to the swimming pool.
As a family we swim three times a week any way no mater whare we are
Washing dishes takes a kettle of water
Bill

 

[chaser]

Folks have had strip washes from a kettil of water for century's
We have managed on sum very extended holidays.
We will be abile to shower when we stop
And ther is always the strip whash option or go to the swimming pool.
As a family we swim three times a week any way no mater whare we are
Washing dishes takes a kettle of water
Bill

Was only just giving my view , you are going to be relying on this setup full time , not going home from a holiday but if you are happy with it, fine

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[Wildbill]

Was only just giving my view , you are going to be relying on this setup full time , not going home from a holiday but if you are happy with it, fine

No problem bud I am fitting another boiler its not so reliant on electronic RCD bords is very robust and it's a carver going under one of the sets thanks for your input owing to my limited command of the written English I can come over as a bit abrupt at times
Bill

 

[Zains Pops]

I once had a Saab 9000 which had a heat exchanger on the windscreen wash system, which used the engine cooling system to heat the water squirted on the windscreen. It really worked well and always gave a really clear smear free windscreen.

 

[chaser]

No problem bud I am fitting another boiler its not so reliant on electronic RCD bords is very robust and it's a carver going under one of the sets thanks for your input owing to my limited command of the written English I can come over as a bit abrupt at times
Bill

That's the one I'd have gone for, simple and reliable

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[ColinandDawn]

@Wildbill

In my Winnebago LeSharo I have what is known as a Motoraid hot water heater. It receives cooling system liquid (anti-freeze and water) through the same kind of system as the cab and the coach heaters.

This hot coolant goes through the two metal pipes running along the drivers side to disappear behind the rear wheel. It enters and departs the Motoraid through the tubing attached to the metal pipes. Inside the Motoraid a coil of tubing submerged in the water heats it before returning to the coolant reservoir high on the firewall, then on to the radiator.

 

[Wildbill]

@Wildbill

In my Winnebago LeSharo I have what is known as a Motoraid hot water heater. It receives cooling system liquid (anti-freeze and water) through the same kind of system as the cab and the coach heaters.

This hot coolant goes through the two metal pipes running along the drivers side to disappear behind the rear wheel. It enters and departs the Motoraid through the tubing attached to the metal pipes. Inside the Motoraid a coil of tubing submerged in the water heats it before returning to the coolant reservoir high on the firewall, then on to the radiator.

That's sumting like what I have in mind with return pipe plumed in near the colent reservoir
Bill

 

[hchris]

ebay item 251980668034 valve or similar and 321635365847 for the control
You may need a relay for the valve.
Had another look no relay needed with valve cr04

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