Hot water

[ColinS]

Used the engine to heat the water in my new calorifier installation for the first time today, and it works just dandy.
Engine is an 18hp Volvo 2002, raw water cooled, standard thermostat. Hot water take-off is after the thermostat. Calorifier is 22 ltrs.
After 25 minutes motoring in a blizzard, the hot water was too hot to touch without a drop of cold (for my girly hands anyway).
So don't believe everything you hear about needing fresh water cooling, or one of the expensive Eberthingywatsits.

 

[sheldon]

Hi was this expensive to buy and fit ive got a volvo 2002 fitted to my sigma , ive been thinking about how to fit a hot water system .

 

[roly_voya]

Simply splice it into the hose to the exhause cooling elbow, before the anti siphon bend if one is fitted. I would include check valves and a means of bypassing the cal if needed in any raw water system as otherwise any problems in the hot water circuit disables the engine.

 

[snowleopard]

For those who fancy giving it a try, remember that with a raw water cooled engine there has to be a flow of cold water to the exhaust to provide cooling while the thermostat is closed. Your water heating will only work if you arrange the pipe so you only get hot water from the block and not the cold bypass water through the calorifier. Tapping into the feed to the exhaust will only give tepid water.

Raw water cooled engines run cooler than FW versions so it isn't essential to have a thermostat on the calorifier and less risk of scalding.

 

[ColinS]

Hi Shelly,
I got a deal at the ECBS - £320 for calorifier, sink mixer tap, shower mixer tap and a few connectors from Penguin Engineering on Hayling Island. All the other odds and sods (hoses, jubilee clips, etc.) came to roughly £80 including a new accumulator. I had to go to my local plumber several times to get the connections sorted, so it would be worthwhile getting everything supplied with the calorifier, that way you can shout at someone else when you find that half the connectors don't fit!
To make the raw water connections from the engine I cut the pipe from the thermostat to the exhaust casting as shown in the picture (mine is a bit neater than this but I do not have a picture yet). The pipe is just a little bigger diameter than standard plumbing fittings so I had to stretch the fittings slightly and reduce the pipe as well, but using brazing rod (Focus DIY) adds plenty of strength to the joint. In an emergency it would be a simple matter to connect a small loop of hose and bypass the calorifier feed/return. The hose was a little tricky to source but I eventually got some locally - PM me if you need their address.

The calorifier sits under the sink like this. Note that the raw water feed pipe is lagged.

The pump is a nominal 8 ltrs/minute, which is plenty enough for the shower head.
The whole job is a bit fiddley, but is now seems to be very worthwhile. Certainly saves all that waiting around for the solar shower to heat up /forums/images/graemlins/laugh.gif

 

[captainslarty]

Nice job Colin !!.. well done