Question 1

What chemicals / treatments do I use in my portable toilet?

Accepted Answer

There are a number of different chemicals / treatments available for your portable toilet.

The first type is added to the waste tank to control smells. There are two different types of chemical — one that reacts and treats the waste and the other is a strong perfume to mask the odour. The odour masking version will last approx 7 to 10 days and then you will need to add more treatment to continue the perfume. The other type is a biological treatment that will release bacteria and it will control smell by breaking the waste down and turning it in to an inert material. The biological version will continue to work for long periods as long as there is waste present to keep the bacteria alive. If you do not use your toilet for long periods then the bacteria will die and you will need to add a new dose.

Both types of treatment are available as either a liquid or sachets. Sachets are a little easier to use as you don't have to measure and you simply drop it into the waste tank. The perfume version is ideal for short term projects/rentals that require a great smell and you are happy to add more toilet additive when the fragrance is no longer noticeable. The biological product is ideal for toilets that are not serviced/emptied regularly — roughly periods longer than 2 weeks.

The second type of treatment is a deodorising disc that is hung in the cabin and release a perfume for approx 2 to 4 weeks depending on brand and conditions. These are ideal when being used by the public as they work out to approx $1 each and don't represent an attractive item to take. If the toilet is for personal use then using a deodoriser available at a local supermarket is ideal for a long term solution. Additionally, using a product equivalent to “Glen 20" achieves an immediate outcome.

We supply commercial strength products designed for large holding tanks over 200 litres. We are often asked about chemical used in camping toilets for use in our large holding tank toilets. Carefully read the product directions as most products are designed for 20 litre camping toilets and often require changing every 5 days. This can work out to be an expensive way to treat your toilet.

Question 2

What is a Rear Evacuation Valve (RSV)?

Accepted Answer

The Rear Evacuation Valve (RSV) is a gate valve installed in the rear of the toilet's waste tank and gives you direct access to the waste tank and its contents.

The RSV is installed in portable toilets that are situated in a location that has access to a sewer connection point or septic system. The RSV enables a gravity empty of your toilet by positioning the toilet above the location you are going to empty the tank into and opening the valve, after connecting a hose (it is quite messy if you don't use a hose). The RSV is also an ideal addition to a trailer mounted toilet that can be positioned next to a sewage access point e.g. recreational vehicle points provided by councils on major roadways used by caravans.

Things to consider:

You generally will need to move the toilet from its normal location to the sewage access point. Do you have equipment to move the toilet eg tractor, forklift etc. A full portable toilet can weigh up to 500 kg.
You will need a hose connected to control / guide your waste to the desired location.
All waste disposal is conditional on your local council regulations.
You can add an RSV to an existing toilet by buying the valve from Merlin. We also sell the hose kits.
It costs approx extra to add the valve to a toilet, however, it will save you the ongoing cost to have the toilet pumped out by a service contractor.
Service contractors will not use the valve to pump out a toilet — they will access the waste tank via the bowl assembly.

Question 3

Why has my portable toilet stopped flushing?

Accepted Answer

Your flush pump has a number of parts that will require replacing over time. We carry spare parts for all our pumps and most likely you will require a diaphragm, inlet and outlet valve for a hand pump. Some foot pumps require a new boot/diaphragm.

Our main pumps are the Whale Compac hand pump (silver handles with a rubber grip) in the Executive and Ultra. Our foots pumps have changed over the years with early models (before 2016) with a rubber cover and internal diaphragm, inlet and outlet. Our recent pumps install with a Merlin Pump have a boot diaphragm.

Our early toilets have a Chimp Henderson pump with a red handle and octagonal diaphragm, inlet and outlet valve.

Question 4

How do you empty a portable toilet?

Accepted Answer

The bowl assemblies on the toilets flip up to give full access to the waste tank and the vacuum pump can then remove the waste. The toilets can be fitted with a Rear Evacuation valve which enables the toilet to be emptied over a dump point. Some units (older fibreglass) will have an access point next to the toilet seat.

Question 5

How often should portable toilets be emptied?

Accepted Answer

On commercial building sites the toilets should be emptied every 2 weeks. In situations where usage is minimal if the correct treatments are being used then you only need empty them when the tank is full. The fresh water tank will need to be filled up regularly.

Question 6

Does Merlin sell spare parts?

Accepted Answer

We have a full range of spare parts for all our products. If you are not sure of what model you have please take a photo and we can let you know which model you have.