Disappearing heating coolant water level?

[bigcol]

Hi just would like to know if any diesel heating system, have disappearing water level in their header tanks.

Ive no evidence of any leaks throughout the system, I’ve checked and check but nothing.

it’s not a lot maybe 1/4 of the header tank, maybe less per month,

 

the only thing I don’t do is seal the tank cap, I put it back in place but don’t lock it off.

 

is this common, does this happen to other peoples systems?

 

be nice to know

[Jen-in-Wellies]

Has this always happened in your ownership of the boat, or is it a new thing?

[Tracy D'arth]

If you are heating the water there will be evaporation losses. How much depends on temperature and the relative humidity of the surrounding environment.

[Tony Brooks]

And when you top it up do you fill the tank to the level mark, full up, or to the level you have worked out for your system.

 

If the loss keeps on going if you don't top it up then you must have a leak or it is evaporation.

[bigcol]

33 minutes ago, Jen-in-Wellies said:

Has this always happened in your ownership of the boat, or is it a new thing?

Since we’ve installed the system

there are no leaks anywhere

it must be evaporation!

would like if other folks heating does the same.

[Tracy D'arth]

1 minute ago, bigcol said:

Since we’ve installed the system

there are no leaks anywhere

it must be evaporation!

would like if other folks heating does the same.

Yes, of course. I have to top up 3 or 4 times a year.

[bigcol]

Thank you for that Tracy, it thought that be the case, but just thought I ask

as I’ve never heard any boater confirming the above apart from yourself.

 

Ta

[Tracy D'arth]

I suppose a lot depends on where the tank is, in a cool area or a warm airing cupboard like mine. Many hire boats have them on the back deck outside.

[Graham and Jo]

Our header tank is in the same area as the Alde boiler and yes, I have to top it up fairly regularly. I have never found a leak. 

 

Cheers Graham

[bigcol]

49 minutes ago, Graham and Jo said:

Our header tank is in the same area as the Alde boiler and yes, I have to top it up fairly regularly. I have never found a leak. 

 

Cheers Graham 

 

👍  makes me feel even better, so it isn’t just me, it’s normal

my header tank is in wheel house, and yes it’s colder than the boat inside of course, it’s evaporation !

[reg]

Was wondering the same as I have fairly recently installed a webasto thermotop as a replacement for my Alde. Though initially  the drop was due to air pockets in the system settling down but it has gone on a bit to long for that. Now I know the answer, thanks for asking the question.