warm cock

[john]

my engine seacock is in a seperate locker to the engine but becomes quite warm when the engine is in use. The only connection between the engine and the seacock is the plastic tubing. Is this normal? (the engine is a sea water cooled bukh 20.) It may not be relevant, but the hot water from the calorifer is always scorching hot, and has to be mixed with cold water before using the taps/shower etc.
Many thanks

 

[mtb]

Thermostat !!! check the heat range and also try it out pop the thermostat in a pan of water and note the temp it opens at .Also there are no other valves that are partially closed are there ?.Had this with a narrow boat turned out to be a valve nearly in the closed position.
Cheers
Mick

<A target="_blank" HREF=http://homepage.ntlworld.com/boats>http://homepage.ntlworld.com/boats</A>

 

[DepSol]

ssshhhhhh with a title like that you will get Pauline B and Jimmie from MOBO chat over here ;-)

Dom

Merry xmas and a happy new year

 

[30boat]

Your thermostat should be opening at 60ºC.If the the calorifier is that hot then you probably have the 75º thermostat fitted or even higher.This is bad news for the engine, hot salt water is very corrosive.The reason could also be ,as was said before, a partially closed sea cock,chek the condition of the impeller as it doesn't like to work in the dry .Is your sea cock a a gate valve?

 

[Johnjo]

I must be very slow!
As I cannot understand why cooling problems on the engine, I.e pump
thermostat etc. would make the seacock get warm,surely it has cold
seawater passing through it when running! possibly understand if when
engine stopped head pressure from the engine or califier was draining
back through the system causing it to feel warm,as I say slow or what?
could someone please explain?

regards mike

 

[Lynette]

Am I doing something wrong?

My engine is indirect cooled but even so some of the same things apply. My thermostat is set to 75deg which the engine handbook says is the correct operating temperature. When running the gauge reaches 75deg as well. As a result the calorifier reaches that temperature and so the hot water, like John's, feels scalding unless mixed with cold.

Am I doing some thing wrong? The handbook warns against running at lower temperatures.

 

[pheran]

Re: Am I doing something wrong?

Surely the temperature of the water in the calorifier is meant to be <font color=blue>scalding hot</font color=blue>....75degC in your case, 88degC ideally (optimum engine running temperature). This is how we get away with relatively small calorifiers, which depend on mixing the 'scalding' with cold water to provide an adequate volume of warm/hot water. This is another reason (besides pressure) that calorifiers are far more robust bits of kit compared with ordinary domestic hot water cylinders.

 

[Robin2]

A few diagnostic questions (not in a logical order):

Is this a new problem - i.e. used it be the case that the inlet sea cock stayed cold when the engine is running - if so what may have changed?

Is it possible that the hot / warm exhaust water is being drawn into the inlet seacock?

Is the problem the same when the boat is moving as when stationary?

Is the water in the plastic tube from the inlet seacock also warm?

Is it possible that water is running out the inlet tube (i.e. backwards) - faulty pump, internal leak perhaps?

Is there an external blockage to the inlet - eg plastic bag?

Have you a water strainer for the inlet water - is it hot?