Oil rads - rating, setting, positioning etc

[Monsoon merchant]

Hi

 

We live aboard, but are unexpectedly about to have to leave our boat for maybe 2 months due to a family emergency. I want to get some thermostat controlled oil filled rads to keep the edge off the temperature for the period we are away. We are hooked up to a decent quality shoreline, and have a cabin space of about 46ft. Would be grateful for any advice on the following:

 

Number of heaters required - fairly open plan layout - I'm guessing 2 would suffice?

 

Position - as far forwards and sternwards as possible?

 

Rating of heaters?

 

Temperature setting? - Want to get heaters with proper variable rather than stepped-type thermostat. What temperature should they be set to so as to give good protection but not mean a second mortgage in electricity bills? Is there a temperature that would obviate the need to winterise the boat?

 

Any recommendations for makes/models that have a proper thermostat on them (used to have one with a digital readout that was really good).

 

Thanks very much.

 

 

[Naughty Cal]

We use a 600 watt oil filled rad in the cabin of our 23ft boat, leaving it on a setting of about a half on the thermostat dial. Last winter the temperature in the cabin didn't drop below 10 degrees but then again it was a mild winter.

 

We plan to do the same again this winter.

[cuthound]

This is my first winter of leaving my own boat "ready to go", so still experimenting.

 

I have two 700 watt thermostatically controlled oil filled electric rads in a 60 foot trad.

 

One is located at the rear, next to the wardrobe containing the calorifier, and the other is almost amidships, located between the bathroom and galley. I think these are the most vulnerable points.

 

At the moment one is plugged in via a thermostically controlled plug set to 5 degrees centigrade and the other plugged in directly. Both rads have their own integrals thermostats set to the minimum setting. I am currently monitoring the situation, to see if it is worth connecting both via the thermostatically controlled plug.

 

This morning the inside of the boat was 4 degrees centigrade, but only the rad on its own integral thermostat was on.

 

Once I know what temperature both thermostats actually work at I will decide on final connection. Ideally both rads connected via the plug in thermostat to maintain a minimum temperature of 5 degrees centigrade.

[Victor Vectis]

We have two 0.5kw oil filled rads that we use when we leave the boat in winter. I think I got them from Tesco a couple of years ago.

One goes in the bedroom at the back of the boat and the other in the middle of the saloon. 51' boat BTW.

 

The thermostats on both are turned down to just above their 'frost' settings. I'm guessing aroundabout 5degC.

 

The only other winterising precaution we do is turn off the 12v and open all the water taps.

 

This subject has been aired before and I'm sure someone will be along soon to talk about invalidating insurance if you leave heaters unattended.

 

Hope this helps.

 

SAM

 

ETA Not sure what the cost in electricity runs to but what ever it is it's cheaper than the cost and hassle of dealing with burst pipes, damaged calorifier etc.

Edited November 6, 2014 by Victor Vectis

[Alan de Enfield]

I know of several boaters that use the tubular 'greenhouse' heaters.

 

3 x 4 foot long in a 60 footer.

 

I think they are about 150w each.

 

Each is screwed to a wooden plank - they cannot fall over and therefore a very low risk.

 

[Naughty Cal]

We have two 0.5kw oil filled rads that we use when we leave the boat in winter. I think I got them from Tesco a couple of years ago.

One goes in the bedroom at the back of the boat and the other in the middle of the saloon. 51' boat BTW.

 

The thermostats on both are turned down to just above their 'frost' settings. I'm guessing aroundabout 5degC.

 

The only other winterising precaution we do is turn off the 12v and open all the water taps.

 

This subject has been aired before and I'm sure someone will be along soon to talk about invalidating insurance if you leave heaters unattended.

 

Hope this helps.

 

SAM

 

ETA Not sure what the cost in electricity runs to but what ever it is it's cheaper than the cost and hassle of dealing with burst pipes, damaged calorifier etc.

That varies between insurers.

 

Ours are happy for heaters to be left unattended.

[scrumpylurcher]

A friend of mine set one up a few years ago and was quite happy until he got his electric bill from the marina, this was or just over £170 for a relatively short period of time. Just be careful and check that the thermostats are working properly

[Naughty Cal]

A friend of mine set one up a few years ago and was quite happy until he got his electric bill from the marina, this was or just over £170 for a relatively short period of time. Just be careful and check that the thermostats are working properly

That sounds a lot!

 

We leave our 600 watt rad and two tube heaters, one in the shower room and one in the engine bay on 24/7 through the winter and we usually use 2x£14 electric cards.

 

ETA: This includes ours usual electric useage of the kettle and oven as well.

Edited November 6, 2014 by Naughty Cal

[bottle]

Monsoon Merchant

 

The heat output, of the heaters, must exceed the heat loss of your boat or they will be on all the time and the boat will still get cold.

 

So anything up to the maximum supply available (shoreline) will do but not less than the losses.

 

Get the largest (watts) available or a combination, the problem will be the thermostats as they are not usually that accurate.

 

The thermostats will need to be set to maintain a temperature of 5° C

[Alan de Enfield]

Even a 500w on all the time can soon eat a fair bit of elctrickery.

 

Our marina (BWML) is 10p per unit so running a 500w heater would be 5p/hour

60p / day

£4.20 per week

£18.00 per month

 

Its no use sticking in a £10 card and leaving it for 3 months.

 

If leaving a boat with a heater on, but without winterising it, it is imperative that you arrange a daily inspection of your boat/ bollard in cold weather - if for any reason the trip - 'trips' and is not reset, then you have plumbing 'full of water' and no heating.

[Monsoon merchant]

Thanks folks for the good advice.

 

Shoreline is metered not card, so will not run out, but tripping is a good point - will ask neighbour to check when we can't.

 

Not sure how to estimate heat losses from boat, so will start with a couple of small rads and see how we get on. Can always add a third if necessary.

 

[Suzie_q]

I know of several boaters that use the tubular 'greenhouse' heaters.

 

3 x 4 foot long in a 60 footer.

 

I think they are about 150w each.

 

Each is screwed to a wooden plank - they cannot fall over and therefore a very low risk.

 

One of those was the heating in my bedroom when I was a kid. Mounted on a plank and left on the floor.

 

Fell out of bed one night and burnt my ear!

Edited November 6, 2014 by Suzie_q

[Victor Vectis]

If leaving a boat with a heater on, but without winterising it, it is imperative that you arrange a daily inspection of your boat/ bollard in cold weather - if for any reason the trip - 'trips' and is not reset, then you have plumbing 'full of water' and no heating.

Difficult if you live on the Isle of Wight and the boat lives at Lapworth!

 

Hence turning the 12v off and draining the taps. If a pipe did burst the ammount of water lost would be minimised and the pump wouldn't be emptying the contents of the tank into the accommodation.

[Alan de Enfield]

Difficult if you live on the Isle of Wight and the boat lives at Lapworth!

 

Hence turning the 12v off and draining the taps. If a pipe did burst the ammount of water lost would be minimised and the pump wouldn't be emptying the contents of the tank into the accommodation.

 

Indeed - many people live miles away from their boats, hence why I said :

 

"that you arrange a daily inspection of your boat/ bollard in cold weather"

 

Surely you could find someone at Lapworth to cast an eye over as they were passing.

[David Mack]

Why do you want to heat the boat? Plenty of boats are left unheated without problem. For a two month absence you should be draining down/winterising everything anyway as you can't rely on heating 100%.

[George94]

Even a 500w on all the time can soon eat a fair bit of elctrickery.

 

Our marina (BWML) is 10p per unit so running a 500w heater would be 5p/hour

60p / day

 

 

Which country do you live in that has 12 hour days? Round here they are all 24. Much better value.

[Plonk]

I may go the greenhouse heater way with our boat as the calorifier is a vertical one built in behind cupboards etc. I can't see any easy way of getting to it without dismantling my Kitchen! We would also like to still use our boat some weekends so a full draindown (if i could do it) would make this difficult. This is our first year of owning the boat and our first winter so I may be missing somthing obvious. I hope being a long way south on the K&A we won't get too many freezing days on the trot! I am tempted by this socket, but it is quite pricy and i'm not 100% sure it would work in the boat. We can use our phones onboard in the marina so it should work. Knowing my luck it would probably be a waste of money. We live about an hour away, but the marina say they would keep an eye on things and make sure the shore line dosen't trip out.

[ditchcrawler]

Filling our system takes minutes, Just turn the water on and let it do the business. Open the tap to let the air out.

At the other end I have a drain on the feed line to the calorifier and draining down takes all of ten minutes. So going to the boat for a few days in the winter is no problem at all. We have never had a shore supply so drain down every winter, normally December onwards, but I did have to rush over in November a few years ago when we had an early cold snap.

[Alan de Enfield]

 

Which country do you live in that has 12 hour days? Round here they are all 24. Much better value.

 

Fair point - well made, not many people live in 'my world'

My way you get twice as many 'full english breakfasts',

[Jo_]

We also prop open the cupboards under the sink and the little doors to the under-cratch area where the water tank is ... just to help the warmer air (from the radiator-heated boat interior) waft round the pipes and waterpump. And make sure the shower pump is gulping free of water.

[George94]

 

Fair point - well made, not many people live in 'my world'

My way you get twice as many 'full english breakfasts',

 

Well, that's a pretty convincing argument for the 12 hour day.

[blackrose]

Two years ago I left a single 2.5kW oil filled rad on my boat all winter until I was able to bring it up to my new mooring in the spring.

 

I left it on the lowest of three power settings (1kW) at 7 degrees C on the built in thermostat. I visited only at weekends and some weeks the outside temperature went well below zero.

 

The heater was left in the centre of a 57ft x 12ft widebeam, so I don't think you really need more than a single 1kW heater.

 

The only other thing I would say is try to find a heater with a manual rather than digital control, because if the shore power trips or there is a power cut and then the power comes back on, a digitally controlled heater won't come back on.

Edited November 10, 2014 by blackrose

[Peter-Bullfinch]

We use two small oil filled rads with a separate thermostat set at 6 degrees. One rad is in the engine room. The other is in the galley. We leave cupboard doors, bathroom and internal doors open to help circulate the air. We don't drain down. The thermostat is roughly central in the boat.

During a couple of recent very cold winters we used just short of £40. I think this is reasonable value and less than the cost of replacing a frozen and split pump.

I checked our arrangements with our insurers and they replied positively. We do call quite regularly to see the boat and sometimes take it out for a couple of days.

I make sure the marina meter has enough credit especially for January and February

The rads are left set at the highest setting and when the thermostat clicks them on they cycle on and off according to their own internal thermostat.

We don't block any mushrooms or vents and even the engine room pigeon box vent is left cracked open. Condensation is minimal. In addition we leave a nappy to soak up bilge condensation. This gets changed each month but doesn't get soggy...just damp.

We live in the north west and I do realise the winters here are relatively mild.

[Naughty Cal]

One word of warning on those digital plug in thermostats. During the very harsh winter we had one freeze off which left our engine bay unheated with some very expensive raw water coolers in there, not good.

 

We now dont bother with them and leave the heaters on 24/7 for what little power they use.

[blackrose]

I don't bother heating the engine room in my boat. If the boat's not raw water cooled (like most NBs), then I don't really see what's going to freeze in there.