Chimney Cowl - possibly leaking

[DavidW]

Hello everyone

 

We had a DRU Global XT fire installed a couple of years ago.  This involved installing a new chimney liner and cowl.  I believe we have a balanced flue - pic attached.  Last year we noticed some water stains on the back of the fire; its fitted with black reflective glass to reflect the flames when lit.  We had thought this was down to condensation.  When we first light the fire, the glass screen does go misty, it then clears with the heat.  Its clear at all other times.

 

Yesterday we noticed more water stains, as through water had run down the chimney and the back of the fire - we did have some torrential rain recently.

 

The chimney has historically been re-pointed, reflashed (leaded) and reflanched when we had renovations done several years ago.

 

Am I right in thinking we do have a balanced flue (this is not my area of expertise) and can the cowl be letting water in?  It is a black metal cowl - see pic (the terracotta one it replaced that sat in the chimney pot is in the garden).  Is this normal that they can leak, or do we need to seal it in some way?  Not sure what else could be causing this - but open to any recommendations you have.

 

Many thanks for any advice.

David

[Marvin]

3Hi @DavidW

 

Yes that type of gas fire has a balanced flu as shown in your photo.

 

Difficult to know the cause. I wonder how the outside surface of the cowl is sealed to the inside edge of the chimney pot against rain. 

 

The pot looks a lot bigger than the cowl. In rain it can run down the cowl all the way to the fire unless it's sealed across the top surface of the pot.

 

That's where I would start.

 

M