Draining calorifier

[Jegs]

Vic S kindly drew attention to this on another thread & I've not found a drain point on the hot tank - remove the immersion & pump out? Does anyone have a similar problem with a simple solution?

Hopeful thanks,

John G

 

[Trundlebug]

I tend to disconnect one of the water pipes at the lowest point.

With plastic pipes, at least they're easy to reseal afterwards.

 

[Hugh Foulis]

I take the plug out and use a Pela type extractor bought from Aldi, taking a pipe off is not practical where it is located.

 

[vyv_cox]

If there is no drain plug, quite unusual, remove the fresh water inlet hose. If access is difficult it is quite OK to break it somewhere else, so long as the calorifier can empty down to a lower point. Open the hot tap to allow air to replace the water.

 

[David2452]

Take off the cold feed, and whilst its off install a drain tap in it for future use.

 

[Steve_N]

Vic S kindly drew attention to this on another thread & I've not found a drain point on the hot tank - remove the immersion & pump out? Does anyone have a similar problem with a simple solution?

Hopeful thanks,

John G

Pump it out using the FW pressure pump - have done mine this way for years.

- take the hose from the water tank off of the pump inlet spigot
- move the outlet hose (taps etc.) across from the pump outlet onto the pump inlet spigot
- attach a length of hose to the pump outlet and route it overboard or into the sink
- open HW taps and turn on the pump..

 

[Jegs]

My thanks to all of you.

John G

 

[Bodach na mara]

Vic S kindly drew attention to this on another thread & I've not found a drain point on the hot tank - remove the immersion & pump out? Does anyone have a similar problem with a simple solution?

Hopeful thanks,

John G

Like Dave (in post 5) I remove the cold feed pipe and also the hot water outlet pipe to vent the tank. I do this despite there being a drain cock in the cold feed near where it enters the tank as it is so S-L-O-W to drain using this. Of course, I do not touch the pipes supplying the heating water to the tank! But you knew that anyway.

 

[Hugh Foulis]

Pump it out using the FW pressure pump - have done mine this way for years.

- take the hose from the water tank off of the pump inlet spigot
- move the outlet hose (taps etc.) across from the pump outlet onto the pump inlet spigot
- attach a length of hose to the pump outlet and route it overboard or into the sink
- open HW taps and turn on the pump..

Bangs head on table in frustration, especially as the FW pump and the shower drain pump are in the same locker. Swap pipe from one to the other and it all goes overboard electrically. Anyone wish to buy a Pela type pump?

 

[Hydrozoan]

Am I correct in my understanding that with a Surecal system, one can use the PRV to drain down? It's my first season with it and I'm not on the boat, but that's what I had planned to do.

 

[essexboy]

Is it not well enough insulated not to bother ?

 

[David2452]

Am I correct in my understanding that with a Surecal system, one can use the PRV to drain down? It's my first season with it and I'm not on the boat, but that's what I had planned to do.

Many calorifiers have the PRV just downstream of the non return valve on the cold feed, if that is the case with yours then the answer is yes, it will take a bit more time though as the passage is not like using a full 1/2" fitting, just turn the PRV knob so it "balances" in the open position. Turn the pump off and taps on obviously.

 

[Hydrozoan]

Many calorifiers have the PRV just downstream of the non return valve on the cold feed, if that is the case with yours then the answer is yes, it will take a bit more time though as the passage is not like using a full 1/2" fitting, just turn the PRV knob so it "balances" in the open position. Turn the pump off and taps on obviously.

Thanks, David - that fits with what I believe Surecal told me (the documentation, if it does address the point, is on the boat and I am not). It also fits with a post I have now seen on a canal boat site which said that they have an NRV where the cold enters (so one cannot drain via the cold feed), but that if the PRV is carefully turned to a raised position "mid click" it will drain. I did not want to come to the point of doing it and have to re-think!

 

[AndrewB]

As a protection against freezing, opening the PRV on the calorifier is easy but won't drain the it right down, unless you can tip it up. Leaving some water in the bottom is probably OK, but might encourage rusting in a steel calorifier while a copper calorifier could still be vulnerable to frost damage.

Even with an NRV, I have successfully drained down my water system, including the calorifier, by switching off the pump, emptying the tank, opening both a cold and a hot tap at a sink, and then using a hand-pump to pump all the water out through the hot tap. (Actually I did it by temporarily attaching the hot water line to the sea-water hand-pump at the sink).

Don't forget the heating coil of the calorifier also needs to be protected. Normally done by adding anti-freeze to the engine coolant and running the engine for a few moments.

 

[David2452]

Don't forget the heating coil of the calorifier also needs to be protected. Normally done by adding anti-freeze to the engine coolant and running the engine for a few moments.

The heat exchanger coil is permanently protected by Anti Freeze as it is effectively part of the engine cooling system, unless raw water cooled of course.

 

[Hydrozoan]

... Leaving some water in the bottom is probably OK ...
Don't forget the heating coil of the calorifier also needs to be protected. Normally done by adding anti-freeze to the engine coolant and running the engine for a few moments.

Yes, I agree that it's probably OK and I'll accept any slight risk on that score. Thanks also for the coil warning, but the engine is not raw water cooled so in this case David 2452's comment applies.

PS I don't know if my query helped the OP as well, or perhaps his concerns had been answered by earlier posts - but apologies for the slight thread drift.