Calorifier

[Alan de Enfield]

15 minutes ago, deckhand said:

We have not specifically emptied the calorifier.  We drained the water tank down to the point of nothing coming out of the taps on last winterise. will this have emptied the calorifier? or is that a specific separate job?  It ended up with us having to turn the pump off in the end as there wasnt enough water for the prv in the end,  Upon 'gently knocking' the side of the tank, it sounds empty but that is only based on listening. Not too sure on what a full tank sounds like so maybe a bit unreliable.

A calorifier needs draining off separately, draining the 'system' will not drain the calorifier.

If you leave the boat in the winter then ensure you do drain off the calorifier as it would be the first or second thing to be damaged (after the instananeous gas water heater)

Edited August 31, 2020 by Alan de Enfield

[Scholar Gypsy]

11 minutes ago, deckhand said:

We have not specifically emptied the calorifier.  We drained the water tank down to the point of nothing coming out of the taps on last winterise. will this have emptied the calorifier? or is that a specific separate job?  It ended up with us having to turn the pump off in the end as there wasnt enough water for the prv in the end,  Upon 'gently knocking' the side of the tank, it sounds empty but that is only based on listening. Not too sure on what a full tank sounds like so maybe a bit unreliable.

The calorifier should empty from the highest point, as that is where the hottest water will be. To drain it you need a draining point on the inlet (and the right side of the one way valve, if one is fitted).  

I have a pump to empty my calorifier, plus assorted valves and hoses, it takes five minutes to empty (and then five mins to fill when I start a winter cruise). The pump also doubles a bilge pump, using the blue inlet hose in the photo below

 

[nicknorman]

9 hours ago, deckhand said:

We have not specifically emptied the calorifier.  We drained the water tank down to the point of nothing coming out of the taps on last winterise. will this have emptied the calorifier? or is that a specific separate job?  It ended up with us having to turn the pump off in the end as there wasnt enough water for the prv in the end,  Upon 'gently knocking' the side of the tank, it sounds empty but that is only based on listening. Not too sure on what a full tank sounds like so maybe a bit unreliable.

Then the calorifier will still be nearly full. With the pump running dry you will just be pumping air into the calorifier at the bottom. The air will rise to the top and be expelled through the taps. Most of the water will remain in the calorifier.

[Ex Brummie]

11 hours ago, WotEver said:

I can’t see that happening. The cauliflower coil isn’t that big; it’d just be acting like a heater coil in a car on a cold day. 

I was referring to a point made about engine temperature being higher with an empty cylinder because there is no heat sink through a full poorly insulated unit.

 

11 hours ago, Tracy D'arth said:

?  Why? 

Asabove

9 hours ago, Alan de Enfield said:

 

If you leave the boat in the winter then ensure you do drain off the calorifier as it would be the first or second thing to be damaged (after the instananeous gas water heater)

I doubt if there are many boats that have a calorifier AND an instantaneous water heater.

[Tracy D'arth]

10 hours ago, deckhand said:

We have not specifically emptied the calorifier.  We drained the water tank down to the point of nothing coming out of the taps on last winterise. will this have emptied the calorifier? or is that a specific separate job?  It ended up with us having to turn the pump off in the end as there wasnt enough water for the prv in the end,  Upon 'gently knocking' the side of the tank, it sounds empty but that is only based on listening. Not too sure on what a full tank sounds like so maybe a bit unreliable.

See my post #4