Forums » Ask a Question

Use this forum to post your questions to our experts – you need to be logged on to do it (you can register here ), then scroll down to the bottom of this page and click the blue Post Thread words

If you can help answer the question, feel free to post a reply – you need to be logged on to do it (you can register here ), then hit the reply button on the thread.

 

To go back to the experts page click here>>

AuthorMessage
DJ
DJ

Posted: Sat Sep 24, 2011 7:37pm

Post Subject: pump out

hi, we have just returned from a 2wk trip on our newly fitted sailaway which has just had its 1st pump out.we noticed a slight smell from the tank that wasnt there before so i blew into the vent inlet to check for a blockage.i then heard water gurgling as i blew into the pipe. when rinse water was put into the breather hose near the end of the pump out not all of it has drained back into the tank due to some of my routing being just below the top height of the tank. my question is will the breather pipe still vent ok with some water in it or should i re-route so it is always full of air.as everything in boating this will not be an easy task hence my question before i start to pull things apart. thanks dave

Tony-B
Tony-B

Posted: Sat Sep 24, 2011 9:37pm

Post Subject: pump out

As you do not tell us what type of toilet you have apart from it's a pump out it is hard to be specific. However in general terms the rinse and vent should be two different systems and if they are both the same it is vital that you ensure no water can lie in the pipe. If it does it will crate an water lock. This may or may not be a problem depending upon toilet type. Tony Brooks

DJ
DJ

Posted: Sun Sep 25, 2011 10:51am

Post Subject: pump out

sorry its a macerator toilet. the holding tank is arranged with 3 inlets. one direct from the toilet, one for the pump out and one for ventilation.

Tony-B
Tony-B

Posted: Sun Sep 25, 2011 11:37am

Post Subject: pump out

If you want to minimise odour then you need to ensure an airflow across the tank in fairly large volumes. This means two breathes at opposite ends of the tank using a large bore pipe. Say 22mm minimum and the larger the better. Your toilet will produce a slurry containing toilet paper fibres. In an ideal world this would be broken down by the microbes in the tank (unless you are using something like non-biological Elsan Blue) but in reality the vibrations from the engine tends to make them fall out of suspension and pack onto the bottom of the tank. To combat this and to minimise the number of times you may need to manually remove such residue I would advocate a flush at the opposite end of the tank to the pump out. If this goes into the top of the tank it should help to wash the residues towards the pump out. It seems to me that you are two fittings short. Most people think only one small breather is all that is required but that can lead to smell but even so you still seem to be one fitting short. To combat smell you need oxygen in the tank to encourage the aerobic bacteria. Its the anaerobic ones that produce smell. However it is doubtful that you can totally eliminate it. Are you aware that the hoses can allow smells to eventually permeate through. To minimise this risk it is important to run the hoses in such a way that no effluent can lie in the hose. For a maccerator I would expect the pipe to rise all but vertically from the toilet and then run downhill all the way to the tank. Traditional Elsan Blue type additive tend to preserve the effluent by killing the microbes. The tougher anaerobic ones survive so producing smells after a few days. Tony Brooks

DJ
DJ

Posted: Sun Sep 25, 2011 1:50pm

Post Subject: pump out

thanks for that tony, i am currently using 38mm pipe for my vent and have placed it at the opposite end to the pump out hose. i have provision to fit a 25mm hose at the opposite end of the current vent positon to allow extra ventilation. so will get my tools out and make a start in the morning. thanks again for your help

Most Read

Newsletter Sign Up

Canal Boat monthly newsletter
Sign up to receive our regular email newsletter

Our Privacy Policy

Like us on Facebook



Follow us on Twitter

Cache: Disabled for this object  Total Queries: 43.  Total Objects: 162.  Total Unserialized: 3. Total Runtime: 0.24 seconds.