Too long to get hot water, Volvo 2003

[TONICK]

Dear Friends. I have a problem with the hot water for the shower. When I run the engine on navigation, I can get hot water in 15 minutes, but when I am anchored, I run it at 1.500 rpm, after one houe, I still can´t get hot water for the shower. Is this normal?. Thank you.

 

[matelot]

if the engine is raw water cooled then its not surprising. if you are running the engine whilst stationary, you wont put any load on it and it wont warm up enough for the thermostat to open and water to flow through the calorifier.

if its an indirect cooled engine then it isnt normal

 

[shmoo]

Yes. It is the load that makes the heat. Try running it in reverse gear, so long as the anchor is well in! It will be better for the engine too.

 

[TONICK]

Exactly, the engine is a raw water cooled , could I suply the problem, increasing the rpm or change the termostate degrees?

 

[VicS]

[ QUOTE ]
change the termostate degrees?

[/ QUOTE ] Do not change the thermostat for a higher temperature one. Raw water cooled engines must run at a low temperature or there will be high rates of scaling and corrosion.

 

[ytd]

Our volvo D2-55 (2003) needs to runs at least at half throttle to make hot water. Haven't tried running in reverse at anchor. Could make the anchor tricky to retrieve since it would be REALLY well dug in.

 

[steve6367]

Sounds about right to me - my Yanmar 3YM only really works when underway and under load. If its not doing any work there is little waste heat to use.

Steve

 

[matelot]

[ QUOTE ]
Exactly, the engine is a raw water cooled , could I suply the problem, increasing the rpm or change the termostate degrees?

[/ QUOTE ]

no - its not speed alone that matters but load. the engine is not getting hot enough to open the thermostat, but I wouldnt recommend a cooler thermostat because the engine would never reach its proper operating temperature and would probably wear out a lot quicker.

I have exactly the same engine but in my case even running the engine under load for a couple of hours, the water doesnt get hot. Its a PITA

 

[jerryat]

Hi Antonio,

I'm afraid I differ from many on here. On my boat, we get hot water at anchor quickly, though not QUITE as quickly as when 'on the move'.

I agree that underway the engine works 'harder' and will heat up a bit quicker, but that in itself can vary hugely as boat speed varies from a little over tickover to full revs. I have found (and frequently recommended on here) that installing a pump between the engine and calorifier very substantially improves the system under ANY conditions. I have used this, and installed them on other boats, for the last 15 years so know it works very well, and some of these have been on fresh-water cooled engines where the pipe runs were lengthy.

I agree with those who suggest putting the engine in astern to provide a 'load', but realistically that load, unless you are very brave(!) is still very low. We cruised full time for the best part of ten years, and always had hot water at anchor after running the engine for charging, checking the anchor etc. Yes, in more spacious anchorages we did put the engine in astern, but this was primarily because of my (possibly out of date) fear that the bores would 'polish' more quickly if I didn't!

I obviously don't know the situation that prevails on your boat, but installing pump may well answer your problems. Certainly the calorifier will then heat up at the same same speed as the cooling water in your engine, so though producing hot water will be marginally slower, it will be much improved.

Definitely agree you leave the thermostat alone, tough do check you have the correct one installed. Contrary to many's views, we've not found a huge difference in the operating temperatures bewteen ourt engine (new Bukh 24) and some FW cooled engines. Certainly even our previous engine (Bukh 20 - 24 years old) produced copious amounts of VERY hot water!

Cheers
Jerry

 

[saltwater_gypsy]

Clean out yer pipes matey.
Try backflushing the feed and return from the engine. Rusty sediment tends to accumulate there.

 

[jerryat]

[ QUOTE ]
Clean out yer pipes matey.
Try backflushing the feed and return from the engine. Rusty sediment tends to accumulate there.

[/ QUOTE ]

Hi, I assume this was directed at the OP?

 

[matelot]

[ QUOTE ]

I obviously don't know the situation that prevails on your boat, but installing pump may well answer your problems. Certainly the calorifier will then heat up at the same same speed as the cooling water in your engine, so though producing hot water will be marginally slower, it will be much improved.



[/ QUOTE ]

I wouldnt be so certain about the pump. Have a few pals with Bukhs (aka steamers) in their boats (Sadlers) and using pumps to help things. Those systems work albeit there is no auxiliary electric pump I'm aware of that is designed to cope with hot salt water

However the Volvo designed calorifier piping is a cr*p system. It takes water from the far side of the thermostat ie only lets water through when the thermostat opens and in the meantime cooling water is provided to the engine block by another route. Trouble is, this route doesnt close as the thermostat opens and its capable of taking the full cooling pump output. So I find that my engine lets a tiny balancing flow through the thermostat depending on load and outside water temperature which is simply insufficient to heat the water.

Its worth trying the pump but even Volvo say the system doesnt work - though I bet they never said it to Moody when flogging them engines.

 

[jerryat]

>> Its worth trying the pump but even Volvo say the system doesnt work - though I bet they never said it to Moody when flogging them engines. <<<

/forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif Ahhhh! Volvo. Yes, a law unto themselves. I hadn't realised the 2003 was one of those with the odd cooling layout. You are right, they are a real bu**er to get hot water from at low load.

Re the pumps, the Johnson range using sealess induction impellers, will work indefinitely with hot salt water. I've used one (for the first 16 years with the old shaft/seals version!) for 25 years and only replaced it once.
Available from ASAP, I've fitted them as part of HW installations on several boats and they've proven superb, even for those who like us, who were full time cruising.

Cheers

Jerry

 

[TONICK]

Right, Could some one lightly explain the instalation of the pump?.

 

[jerryat]

Hi Antonio,

I have PM'd (private messaged) you. To read the message, click on the little flashing 'flag' just under 'Logout' on the main banner, then on 'Received messages', then on the one marked with my name ('Jerryat') alongside it.

If you wish to reply, click on 'Reply to this message' (bottom left) type your message, then click 'Submit', check the message, then click 'Ok, submit'. That's it!

Cheers

Jerry