250 volt fuse

I presume you mean Dometic' and not 'domestic'?

Slow Blow is the answer

Installation Instructions for CDMW12W and CDMW12B ...

https://www.dutchmen.com > user > ownermanual
PDF
OBSERVE ALL GOVERNING CODES AND ORDINANCES A 120 VOLT, 60Hz. AC ONLY. 15 OR 20 AMP. FUSED ELECTRICAL SUPPLY IS REQUIRED. (TIME-DELAY FUSE IS RECOMMENDED.).
2 pages

..

I suggest you check that voltage as I just looked at specification and it said the fire is rated at 1500 watts at 125 volts and for that a fuse of 15 amps is about right.
If it really is 250 volts a fuse of 10 amps is the nearest commonly available to the ideal of 8 amps (slow blow types).

No! Unless you have read it wrong and it should be 320V. You can go higher than 250 volts but not lower. And you can go lower say to 10A and say up to 16 or 20A, though you should stay around 15A to be safe. If you do fit a 10A fuse at 250 volt and it blows straight away then it won't be the fuse that is faulty, but something inside the amp that has gone. As fitting even a 15A 250V will do the same. A 32 volt fuse in the mains section will burn out in a fraction of a second.

There is a ceramic fuse inside (automotive style fuse) which may blow in the event of
a power surge or failing magnetron. These are available at most radio shack or
appliance parts store for a couple of dollars. Make sure to unplug unit before removing
cover and be very careful around the capacitors as they can retain a high voltage
similar to an electric fence. The fuse will be ceramic with metal ends , replace with
equal value amps and volts (stamped on metal bands at each end) for example
5A 250 V is read as 5 amps at 250 volts. These are slow blow fuses and cannot be
replaced with just automotive fuses . Hope this proves helpful

Replace the fuse...not what is written on the circut board....Radio Shack or any electrical repair outlet will have fuses.

You can get the fuse at Radio Shack. Part number 270-1065. It is a 3.15 amp 250 volt slow-blow fuse.
If you replace the fuse and it blows again, you need a new A circuit board part number 829606005.

That would depend on the mains supply of the unit in question. If it has a 250 volt mains supply use a 250 volt fuse. However the crucial one is the amp rating. If it was a 300ma fuse installed a fuse no greater than that should be used. If it was a 2amp fuse a 1.5 could be used, but not a 2.5. Many fuses are fitted with a 250 volt rating in areas where it would never go higher than say 50 volts, such as in the secondary winding of the transformer.

Look at he fuse on the very end of the fuse there are some numbers. Amps and volts, go by that and replace it with the same exact fuse. If not , you can damage the equipment

If you need further help, I’m available over the phone at https://www.6ya.com/expert/craig_3fa289bf857b1a3c

Well, take good look at the Fuse itself on metal area.
If it says AGC, then fast acting.
If it says MDL, then Slow Acting.

If you cannot figure it out, then just use Fast Acting since it is more commonly used in smaller Receivers and Amplifiers and Fast Acting will cutoff faster (compair to Slow Acting) if there is any unknown Prblem with Chassis.

F101 is 8 amp / 250 volt slow blow
F103 is 315 mA / 250 volt slow blow