Log in
Article search:

Q & A

Water tank

I have no breather on my integral water tank. Not fitted by builder. Should there be one?

Asked by: C Barlow  | 10.55am, Monday 14 November

WW says:

The breather pipe allows air to escape from the tank as it fills with water from your hose. In some cases, it also acts as an overflow in case you forget to check how full the tank is getting.
Provided the inlet pipe is greater in diameter than the hose you use to fill the tank, air should escape past the hose. In some situations, however, you may get an air lock which could cause a blowback or it may be difficult to fill the tank completely.
You should be careful not to over fill the tank because, depending on the location of the tank filler, you may find that contamination from around the filler runs back into the tank as the water subsides.
So, the tank should have a breather but, with care, you should be able to manage without one.

Graham Booth  | 2.01PM, Monday 14 November

The other concern is, a breather pipe lets air in as you empty the tank... so although unlikely, if the filler cap was a perfect airtight seal, the water pump could, potentially, struggle to remove the water, as a partial vacuum could form.
depending where the filler cap is located, it might be possible to attach a breather to the cap- such as a mesh-filtered fuel tank breather fitting. However, avoid this if it would cause a trip hazard, or where standing water could accumulate (or canal water) as this could lead to microbial contamination
My breather pipe, on my integral tank, was hidden away in a corner of an underseat locker- so you might find one in a strange place!

Mark Langley  | 5.36PM, Monday 14 November

An 'integral water tank' uses a part of the hull, often the bow locker or the enclosed space under the well deck, rather than a separate tank. There will be a lid or access panel to enable cleaning and painting. If there is no breather vent then you need to ascertain where air is getting in to allow the water out. It might be as well to check the panel seal to ensure that dirt is not getting into the water. If it is a bow locker type tank, it will have a hinged lid like a gas locker, with an upstand to prevent the ingress of dirt.
If there definitely is no vent of any type you might have a collapsible liner fitted inside the tank. The inlet and outlet pipes join directly to the liner and it will change shape as the water is pumped out, this however is an expensive option not often found on narrowboats.

Rupert Smedley  | 7.57PM, Monday 14 November

You must log in to post an answer.