Frequently Asked Questions


The best way to check the microwave function is to put a Litre of cold water in a container.

Measure the start temperature

Run the oven for 33 seconds

Measure the finish temperature.

The difference in start and end temperature will give you a measure of how much power the oven is developing. 

1000W = 5.0 Deg C

1100W = 5.5 Deg C

1400W = 7.5 Deg C

1800W = 10.0 Deg C

2100W = 11.5 Deg C

2400W = 13.0 Deg C

First of all this question only applies to standard microwaves without convection heat eg RMS, RCS, RFS, DEC, MOC & MSO Models

For Convection and Expresschef Models see seperate FAQ eg DS1400, JET514, MRX,MXP 

Most Plastics and ceramics are OK . Despite what some will tell you you CANNOT use metal containers or foil in a Menumaster commercial microwave. In general these are more powerful than domestic ovens and the microwave coverage pattern is designed not to be affected by other metal in the oven. Using foil or metal will cause arcing and will destroy the magnetron (The part that makes the microwave energy) . When we service an oven we can tell if this has been happening. This will also void the warranty. 

Also running the oven empty will cause the same problem. 

So how do I check a container if its not labelled as microwave safe ? 

The best  way  is to place the empty container/plate in the microwave next to a glass of water.

Run the oven for 30 secs

Open the oven and check the container/plate - If its still cool then its not being heated by the microwave and should be fine to use. ie the water will be heated but not the empty container. 




This question applies to Menumaster Expresschef models DS1400, JET514, MRX and  MXP Ovens

Generally plastics are not suitable as they don't have a temperature range up to the 250C required for these models. 

For Ceramic plates and containers the same rules apply as a standard microwave. NB MOST white glazes are OK and MOST coloured glazes contain metal. Best way to check is in a standard microwave per the previous FAQ. NB these ovens are also more powerful microwaves so its more important to get the correct plates/containers. 

These ovens CAN use metal cookware as they have been designed for it however there are some rules that apply.

- Trays should not touch the sides or door of the oven

- Sides cannot be higher that 38mm (1 1/4 ")

- Corners cannot be folded (ie baking trays often have folded corners)

- Top edges cannot be rolled edge 

- Foil is not OK 

Like the standard microwave, running the microwave empty or using the incorrect container will damage the oven and void the warranty.

We stock a range of suitable trays and baskets.

As the ovens are built in the USA Gastronorm sizes don't readily fit as they are more designed for Bun Pan sizes. 










Menumaster ovens use a hidden stirrer system to move the microwave around inside the oven cavity to ensure even coverage throughout  hence they do not need a rotating plate like a domestic oven. 

Different models have different distribution arrangements which can affect the operation as listed below. 

RMS Models These oven are bottom fed ie the microwave enters the oven from under the ceramic base plate. This works well as it will heat muffins and slices from the bottom and up into the centre. NB it can be problematic with liquids though eg I had an issue with a rest home heating jugs of milk which tended to boil over.

RCS Models  These ovens are top fed ie the microwave enters the oven from above the plastic antenna shield at the top of the oven 

RFS518, DEC14, DEC18, DEC21, MOC5241 These ovens are Dual Magnetron ie they are top and bottom fed at the same time. There are Microwave stirrers below the Ceramic base and above the top antenna shield. 

DS1400, JET514 These Expresschef ovens are top fed from above the ceramic/glass antenna cover in the cavity roof

MXP The MXP has  a ceramic cover each side of the oven which covers the stirrer and microwave entry. 


The plastic cover in the top of RCS, RFS and DEC models can melt and need to be replaced. This is called an Antenna cover as it protects the Antenna that distributes the microwave and in some models it is part of the required air circulation. 

Usually this can be replaced by the customer without a service visit unless there are other issues.  Contact Cooktech with the Model and Manufacturing number and we can get you the correct one. . 

Why did this happen ? Two things will cause and antenna shield to melt and burn.

1. Food and grease buildup that has not been cleaned off

2. Running the oven empty

Once the plastic has melted and turned black the carbon will continue to be heated by the microwave and the damage will continue to spread.

To replace the antenna shield we need to remove all the old one and clean the area with detergent and scotchbrite to remove the carbon and grease.

Then replace the Antenna shield with the new one. 




Standard microwaves without convection heat are really easy to clean. Spray the interior with a detergent solution (Dishwash liquid and water in a spray bottle) and wipe out the interior. You can use green scotchbrite on stubborn food etc. 

NB Keeping the interior clean helps the microwave work better apart from being sanitary.  Food and grease on the interior of the oven will be heated by the microwave and take away from the food. Also if left too long on the plastic parts it will burn and cause a premature failure. 

Dont forget the top - Everyone always forget the top !!

The Express chef ovens should NOT be cleaned with caustic solvents as they will damage the oven. ie Models DS1400,JET514,MRX, MXP

We supply Ecolab Greaslift in a convenient 750ml Spray bottle

Usage as below:

Ecolab Greaselift usage guide for Menumaster Oven cleaning

After closing for the day put the Oven (JET,MRX/MXP) into cool down mode 

ie turn the oven off on the keypad Do NOT turn the oven off on the wall until it has     completed the cool down cycle and the fans have stopped. 

Ensure surface is warm not hot before use (max 55°C).  

After the cooling fans have turned off on the cool down cycle it will be close to this temperature but may need a few more minutes to cool. If the oven walls are still too hot to touch or the cleaner “fizzes” when sprayed on then it needs more time.   

Spray Greaselift onto surface, covering soiled area completely with foam. Spray the walls and roof of the oven Do NOT spray into the vent grills - Spray on a cloth and wipe onto the grills

Allow Greaselift to penetrate grease deposits for 3 - 15 minutes depending on the soil level.

For serious cleaning you can leave it on overnight. For deep accumulations on the oven base spray until wet and then place a cloth on top to hold the moisture on the surface. 

Leave between 15 Mins to overnight. 

Wipe off dissolved and loosened grease with a scotch brite scrub pad or a damp cloth. 

Rinse surface with clean water.

Greaselift does not require gloves, goggles or face mask. However it is an effective degreaser so gloves will prevent your skin getting dirty and dried out.  Caution should be used when cleaning warm surfaces. If you wipe out the oven with a mild detergent every day when cold a weekly clean with Greaselift should be ample to keep the oven very clean and it will last a LOT longer between services

Reorders/Questions  Please contact CookTech 09 444 9078 menumaster@cooktech.co.nz


Please Contact Cooktech for service in Auckland metro area. 

If you are outside Auckland metro then contact us and we can give you the nearest service agent in your area.

Live somewhere remote and you have a favourite electrical/electronic service company you love ...let us know we are always on the lookout for great service companies to work with and customer referrals have always worked the best for us..

AMANA was the brand we distributed previously. The Menumaster company was purchased by AMANA some time ago and then by ACP Solutions.

ACP distributes as AMANA in the USA.

All 50Hz international product is now branded Menumaster. 

While any AMANA branded product in NZ is now getting on a bit we still have parts for some models. 

We regularly supply parts and service for units that are 10+ years old. 

While parts for  older models do eventually become NLA (No Longer available) from the factory around 7+ years after the last manufacture minimum, typically 10 years and often there are equivalents longer. 

We don't discard older parts until they are used up or there aren't any left in the market.

We regularly surprise service companies and customers with what we have available 

Contact us and we will see how we can help - All our parts are stocked in our Auckland warehouse.  

If its a current part and we don't have it (happens VERY occasionally) our policy is to Fedex/UPS it in from the US at no extra charge to you

As we stock all our parts in our North Shore Auckland warehouse generally overnight depending on local courier delivery. 

Our cutoff for NZC overnight is around 4pm weekdays.

For the South Isl sometimes a 2 Day service is substantially cheaper for bulky or heavy items eg Transformers.

If its a current part and we don't have it (happens VERY occasionally) our policy is to Fedex/UPS it in from the US at no extra charge to you


Certainly . All the operations manuals for current models are listed on the this site in the manuals section 

Later Models of the DEC and all Expresschef models can load programs from a USB drive 

If you are programming a number of ovens the programs can be "cloned" using a USB drive. 

If you are creating complicated programs, want to add names and pictures there is a free software available from ACP.

Windows and MAC versions. Contact us for a copy of the latest version or download it here 

We are always happy to assist with this as required - There may be a charge depending on whats required etc 


Need help?

We have added answers to some commonly asked questions. If you have a question thats not here please let us know and we will add it. 

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