Dehumidifier fire hazard

[Steve S]

I received the safety warning from Lymington Harbour Commission today, I'm sharing it as I think everyone that uses a dehumidifier in their boat should be aware

 

IMPORTANT SAFETY MESSAGE CONCERNING DEHUMIDIFIERS

It has come to our attention that the cause of a fire in a vessel moored in the Berthon Marina last summer was an owner supplied domestic dehumidifier which had been modified to drain permanently into the bilge. It was not designed to be used on a boat, nor for 24/7 unattended use.
Subsequent investigation identified further owner supplied domestic dehumidifiers with scorch marks from overheating. Wider research has revealed that these were by no means isolated incidents with a number of serious fires having previously been highlighted in boating press.
The purpose of this communication is to bring this issue to your attention and to request that if you are using a dehumidifier on your boat when on a LHC berth, you only use a dehumidifier that has been designed to run unattended 24/7 and at low temperatures. We understand that insurers are now increasingly incorporating a requirement for dehumidifiers to be rated for marine use as a condition of cover.

Further precautions: -
1. Avoid compressor dehumidifiers as temperatures below 18°C (65°C) can cause the coil to get too cold and freeze up. A frozen coil is a known cause of compressor overheating. A Desiccant dehumidifier that has been designed to run unattended 24/7 and at low temperatures is recommended for use on boats moored in the UK where cooler temperatures can prevail.
2. Ensure that the unit is operated and maintained in accordance with the manufacturer’s instructions. Most units will have a requirement that they are only used on a level flat surface and are well ventilated.
3. Be aware that in strong winds boats will heal over and that certain designs of dehumidifier will be more prone to toppling over which in itself creates a fire risk, particularly if ventilation becomes obstructed as a result. Consider fixing to prevent.
The link below gives an example of a Desiccant dehumidifier which has been specifically designed for boat use.
https://www.justfans.co.uk/dryboat-db1200-inox-litre-desiccant-dehumidifier-p-2064.html
4. Before plugging in to a pontoon electricity supply, please check that the dehumidifier is upright and well ventilated, particularly if you have been to sea or been lifted for a scrub/dry storage etc.

 

[great white]

Thanks

 

That is why I use mine on the deck into its own small tank , rather than leaving it balanced to drain into a sink as I see on some yachts.

 

At least if I cannot get to the boat for a few days it turns off when the tank is full.

 

I leave a greenhouse heater on as the unit works better that way.