Overwintering, heating control.

[Tigerr]

We've had some experience over the years of overwintering mistakes, so now asking for some counsel on thermostat settings.

We are going to leave the boat until March. Obvs, usual overwintering prep re water etc. 

It's moored on a shoreline power. Ever since many years ago leaving her without heat, I prefer to avoid a complete freeze internally and in the engine room. Protects the fabric of the boat as well as the pipes. 

I have used greenhouse tube warmers. Also oil heaters, but that's an expensive wasteful option I think. 

But I'd like to avoid wasting heat so this year have some thermostat switches for the greenhouse warmers. One for the engine, one for the back and one for the front. Aim is to keep just above a freeze, no more. 

Question is, to others who have used the same approach - what temperatures do you set for the heaters? I was going to go for on at 2C, off at 4C but then I wondered if I'd missed the impact of dropping temperature and the weak heat output of the warmers. 

Advice? 

[booke23]

I’d go for on at 5c…..like you say the heaters are only low output.

[Alan de Enfield]

Just now, Tigerr said:

We've had some experience over the years of overwintering mistakes, so now asking for some counsel on thermostat settings.

We are going to leave the boat until March. Obvs, usual overwintering prep re water etc. 

It's moored on a shoreline power. Ever since many years ago leaving her without heat, I prefer to avoid a complete freeze internally and in the engine room. Protects the fabric of the boat as well as the pipes. 

I have used greenhouse tube warmers. Also oil heaters, but that's an expensive wasteful option I think. 

But I'd like to avoid wasting heat so this year have some thermostat switches for the greenhouse warmers. One for the engine, one for the back and one for the front. Aim is to keep just above a freeze, no more. 

Question is, to others who have used the same approach - what temperatures do you set for the heaters? I was going to go for on at 2C, off at 4C but then I wondered if I'd missed the impact of dropping temperature and the weak heat output of the warmers. 

Advice? 

 

I have 2x 375watt tube-heaters and set the temperature to come on at 5 degrees, they do say that the accuracy is +/- 1 degree so it could be 4 degrees. They will come on when the temperature is falling and it will probably continue to fall for some time until the heaters start to tke effect, so it could get as low as (say) 2 degrees, the heaters start to have an effect on the temperature and as it rise to 5 degrees (+/- 1 degree) they will switch off.

 

I think if you set them at 2 degrees it'll actually drop below zero before the heaters start to have much effect - what size are your heaters ?

[Tigerr]

2 minutes ago, Alan de Enfield said:

 

I have 2x 375watt tube-heaters and set the temperature to come on at 5 degrees, they do say that the accuracy is +/- 1 degree so it could be 4 degrees. They will come on when the temperature is falling and it will probably continue to fall for some time until the heaters start to tke effect, so it could get as low as (say) 2 degrees, the heaters start to have an effect on the temperature and as it rise to 5 degrees (+/- 1 degree) they will switch off.

 

I think if you set them at 2 degrees it'll actually drop below zero before the heaters start to have much effect - what size are your heaters ?

Mine are small, but your advice is exactly in line with what I thought. Need to advance the 'on' time to account for low heat output in a falling temperature situation. I will set for 5 to come on, and a bit lower to come off. If there's a serious freeze, which these days seems less each year, I'll go and adjust, add the oil heater. 

Thanks, that's the advice I was looking for. 

[Tony Brooks]

Just read your insurance documents because it has been reported that at least one insurer said using a non-marine approved heater would invalidate the insurance. This may have changed, but please check.

[David Mack]

Then try and find an insurance approved heater!

[Tony Brooks]

22 minutes ago, David Mack said:

Then try and find an insurance approved heater!

 

No, find an insurer who does not impose such conditions.

[Momac]

5 degrees for the tube heater to cut in for me also.

 

In recent winters it has been rare for the heaters to cut in (with the boat in the water). This is based on monitoring energy use  which I can do remotely from the boat via the marina system.

I also use a dehumidifier which uses quite a lot more electrical energy compared to the rarely needed heaters - about 50 to 60 pence per day at the moment (on an unoccupied boat).

 

 

[GUMPY]

I used to use 2x750W radiators* on a stat set at 4degC. The boat would also send me an SMS if the temperature inside dropped below 2degC**, thus telling me if the rads had failed in their duty so I could fire up the Eberspacher remotely.

 

 

*At present sitting in my garage doing not a lot.

** It would also send a. SMS if the shore power was disconnected and if the battery SOC dropped below 80%

[Momac]

I also have not put the heaters on yet but the dehumidifier has been in use a couple of weeks.

In recent years  damaging frosts seem much less frequent but there are always exceptions. I should really get the heaters plugged in before the end of November .

[IanD]

The heating on mine (diesel boiler, controlled by a Nest thermostat, plugged in on shoreline) is set to come on at 4.5C as frost protection, and there's no way to change this.

 

In the last month it's come on just once, for 30mins at 11pm last Saturday when it was pretty cold overnight.

[cuthound]

I use two 750 watt oil filled radiators on a thermostatic plug set to 5 degrees C  (one near the water pumps and one near the calorifier) plus a Meaco DD8L dehumidifier set to come on when the relative humidity increases above 50%. I block the mushroom vents with sponges and cover the low level vents with cardboard to stop the dehumidifier from drying out the world.

 

I've used this arrangement for 9 years, after my first winter with the boat when I used the heaters but found that dampness had caused some doors to swell and stick. The dehumidifier also prevents dampness and mould from affecting soft furnishings, so well worth the running cost IMHO.

 

It also means one can take a winter cruise at short notice as it takes 5 minutes to winterise or de-winterise the boat.

Edited November 17, 2023 by cuthound
To add the last paragraph

[ditchcrawler]

14 hours ago, GUMPY said:

I used to use 2x750W radiators* on a stat set at 4degC. The boat would also send me an SMS if the temperature inside dropped below 2degC**, thus telling me if the rads had failed in their duty so I could fire up the Eberspacher remotely.

 

 

*At present sitting in my garage doing not a lot.

** It would also send a. SMS if the shore power was disconnected and if the battery SOC dropped below 80%

Did you turn the heating on last night for the new owner? ☺️

[Rob-M]

Our thermometer showed it had hit 4.5 recently, will set the radiators on 5 Deg switches when we next go home.

[GUMPY]

15 hours ago, ditchcrawler said:

Did you turn the heating on last night for the new owner? ☺️

I deliberately locked my phone number out of the controller and deleted the number from my phone when I sold the boat. Decided there could have been to much fun to be had randomly turning their heating on😱

[Ken X]

On 16/11/2023 at 20:36, Tony Brooks said:

 

No, find an insurer who does not impose such conditions.

On a similar vein, we often go boating during the winter and noted our house insurance has a minimum house temperature requirement of 15 degrees whilst we are away.  I was hoping for a bit lower than this but there you go.

[SnippetySnip]

On 17/11/2023 at 07:46, GUMPY said:

I used to use 2x750W radiators* on a stat set at 4degC. The boat would also send me an SMS if the temperature inside dropped below 2degC**, thus telling me if the rads had failed in their duty so I could fire up the Eberspacher remotely.

 

 

*At present sitting in my garage doing not a lot.

** It would also send a. SMS if the shore power was disconnected and if the battery SOC dropped below 80%

I’m thinking of a setup like this for the boat this winter, what kind of thermostatic controller did you use?

[GUMPY]

1 hour ago, SnippetySnip said:

I’m thinking of a setup like this for the boat this winter, what kind of thermostatic controller did you use?

It was just a digital 13amp thermostat plug.

Just looked and there is no makers name on it. Plenty on Amazon though.

 

[Alan de Enfield]

1 hour ago, GUMPY said:

It was just a digital 13amp thermostat plug.

Just looked and there is no makers name on it. Plenty on Amazon though.

 

 

I decided to use a mechanical thermostat plug as, if the power goes off I was led to believe that a 'digital' one loses its settings - maybe I was worrying unduly, but we do get occasional power-cuts at the marina and being 200+ mile away I just want it to 're-start' again when the power returns.

 

I went for one like this, and checked it worked again after the power was cut and came back - it does.

 

Just dial in the cut-in temperature.

 

[Tony Brooks]

27 minutes ago, Alan de Enfield said:

 

I decided to use a mechanical thermostat plug as, if the power goes off I was led to believe that a 'digital' one loses its settings - maybe I was worrying unduly, but we do get occasional power-cuts at the marina and being 200+ mile away I just want it to 're-start' again when the power returns.

 

I went for one like this, and checked it worked again after the power was cut and came back - it does.

 

Just dial in the cut-in temperature.

 

 

 

Absolutely, dead simple to set - on/off & set temperature, whereas the digital things on Amazon seem far more complicated. One of my digital propagator thermostat keeps its setting when the power is off, but I think it and the others may use a small, fixed rechargeable battery, so when that fails the settings go.

[GUMPY]

32 minutes ago, Alan de Enfield said:

 

I decided to use a mechanical thermostat plug as, if the power goes off I was led to believe that a 'digital' one loses its settings - maybe I was worrying unduly, but we do get occasional power-cuts at the marina and being 200+ mile away I just want it to 're-start' again when the power returns.

 

I went for one like this, and checked it worked again after the power was cut and came back - it does.

 

Just dial in the cut-in temperature.

 

Depends on the digital one mine keeps its settings year on year

[booke23]

I have one of these and it also remembers it's settings....even when I've left it unplugged for months. 

 

 

 

[SnippetySnip]

Thanks to everyone for all the suggestions for thermostats that's really helpful. Do you run the radiators at like max power and let the thermostat do its work cycling it on and off? Or do you take a more softly softly approach with a lower setting on the rad and let the thermostat keep it on for longer? I guess that's a question of taste!

 

 

On 17/11/2023 at 07:46, GUMPY said:

The boat would also send me an SMS if the temperature inside dropped below 2degC

 

 

This sounds really smart, what type of system do you have set up to do this? Thanks!

[GUMPY]

31 minutes ago, SnippetySnip said:

Thanks to everyone for all the suggestions for thermostats that's really helpful. Do you run the radiators at like max power and let the thermostat do its work cycling it on and off? Or do you take a more softly softly approach with a lower setting on the rad and let the thermostat keep it on for longer? I guess that's a question of taste!

 

 

 

This sounds really smart, what type of system do you have set up to do this? Thanks!

I ran the rads at maximum and let the stat take care of it all.

As for the rest of it it's something I built by combining available bits.

The main control was one of these

https://gsm-activate.co.uk/product/gsm-auto-dialler/

The relay output was connected to my Eberspacher so it could be remotely switched.

The inputs were connected to:

1 a Smartgauge set to alarm when SOC dropped below 80%

2 a relay connected to the main power input that switched if the power went off

3 a 12v thermostat

4 the relay in the Victron Combi

4 really duplicated 2 .

It could be used for all sorts of inputs.

 

[booke23]

32 minutes ago, GUMPY said:

I ran the rads at maximum and let the stat take care of it all.

 

Ditto.