Probably a stupid question

[GDPR150987]

Ive been digging up old threads on how to winterise the fresh water system and it appears the general consensus is to drain down the potable water tank and leave the taps open.

So taday I paid a visit to the boat and turned on the water pump and opened my taps until water stopped flowing so presume the tank is now empty. My question is if I decided to use the boat will the hot water cylinder get damaged as the engine heats it up during use and now its empty. I obviously wouldn't turn the 240v immersion on but am worried about using the engine and possibly damaging the internals?

Boat is a MF805

Thanks

 

[Medskipper]

Ive been digging up old threads on how to winterise the fresh water system and it appears the general consensus is to drain down the potable water tank and leave the taps open.

So taday I paid a visit to the boat and turned on the water pump and opened my taps until water stopped flowing so presume the tank is now empty. My question is if I decided to use the boat will the hot water cylinder get damaged as the engine heats it up during use and now its empty. I obviously wouldn't turn the 240v immersion on but am worried about using the engine and possibly damaging the internals?

Boat is a MF805

No it should be fine, the water in the hot tank is heated in the same way as your immersion tank at home from a central heating system. A pipe runs through the tank and the heat in the pipe is transferred to the water inside the tank. If the tank is empty it will not do anything! But don't turn on the 220/240 immersion on! That's like turning on your electric kettle with no water in it!

 

[GDPR150987]

Thanks Medskipper. Much appreciated. Thats going to save me the hassle of filling up the water tank now everytime I use her throughout the winter months.

 

[Momac]

It would be a bit daft if the design was such that you could not run the engine if you used all the domestic water.

The calorifier tank may not be completely empty of water . But I have done the same as yourself and not experienced any frost damage to the tank. And I am well North of Plymouth (so is my boat).

There might be a drain valve at the bottom of the calorifier to allow the last of the water to be drained off.

 

[GDPR150987]

Good point. I guess it was a stupid question as I feared. Thanks.

 

[rafiki_]

I doubt if the calorifier is empty. I had to pump mine dry, using the dinghy plump into a hose off a tap. However, as you are on the sea, it is unlikely that you will have a problem. Best thing to do is to use low wattage tube heaters in the engine bay and near the calorifier, with a thermal plug, set to ping on below say 4 or 5C. This is what I have done in the past, and it worked down to -19c one winter.

 

[kashurst]

worth emptying the calorifier over winter if you aren't using it. Often there is a drain valve you can put a length of hose pipe on to drain it down. The thing I always used to forget is the transom shower if you have one - these freeze and break easily, need to take off the shower head or disconnect internally if its easier. I am always wary of relying just on heating tubes - shore power in many marinas is a bit iffy.

 

[alt]

Yes, make sure to drain the calorifier to be safe!

Mine has a drain plug, yours may too:

 

[GDPR150987]

Thanks guys for all the advice.

Forgot all about the bathing platform shower I'd better get back down there and sort that out too. Re the calorifier drain I had a quick look through the manual and spotted it has a drain valve like yours which appers to drain into the rear sump so Ill do that whilst Im there too. Thanks for the help chaps :encouragement: