Webasto\Eberspacher 4 or 5 KW?

[blackrose]

I've just bought one of those refurbished 5kW Thermotop C kits from ebay for £390. I know IMEA has warned us against them, but I've heard some members reviews and they had good results, so it's worth a punt for the price.

 

https://www.ebay.co.uk/itm/Webasto-Thermo-Top-C-KIT-5kW-DIESEL-WATER-HEATER-12V-Boat-Motorhome-3-mths-WARR/223132361040?hash=item33f3b9a150:g:rmwAAOSw899bkCCp

[Motters79]

13 hours ago, blackrose said:

I've just bought one of those refurbished 5kW Thermotop C kits from ebay for £390. I know IMEA has warned us against them, but I've heard some members reviews and they had good results, so it's worth a punt for the price.

 

https://www.ebay.co.uk/itm/Webasto-Thermo-Top-C-KIT-5kW-DIESEL-WATER-HEATER-12V-Boat-Motorhome-3-mths-WARR/223132361040?hash=item33f3b9a150:g:rmwAAOSw899bkCCp

I have to admit I'm very tempted. Its a 5kw admittedly which goes against the advice somewhat, but for the price, if it works (feedback and comments on here indicate it will be fine) then its. Considerable saving. Providing I switch it of when up to temp and don't allow cycling then it should do the job. I'll also go for 4 double rads to make sure it has something to do. 

 

Anyone else bought recon unit? Any tales to tell good or bad?

[mrsmelly]

2 hours ago, Motters79 said:

I have to admit I'm very tempted. Its a 5kw admittedly which goes against the advice somewhat, but for the price, if it works (feedback and comments on here indicate it will be fine) then its. Considerable saving. Providing I switch it of when up to temp and don't allow cycling then it should do the job. I'll also go for 4 double rads to make sure it has something to do. 

 

Anyone else bought recon unit? Any tales to tell good or bad?

This is what I bought from a similar online seller called mp and h. Massive positive feedback. Everything required apart from header tank which cost me about seventy quid. Hasn't missed a beat yet. Fit plenty of big rads they will all get hot. for secondary heating and summer hot water etc has proved a very good buy.

[Motters79]

16 hours ago, blackrose said:

I've just bought one of those refurbished 5kW Thermotop C kits from ebay for £390. I know IMEA has warned us against them, but I've heard some members reviews and they had good results, so it's worth a punt for the price.

 

https://www.ebay.co.uk/itm/Webasto-Thermo-Top-C-KIT-5kW-DIESEL-WATER-HEATER-12V-Boat-Motorhome-3-mths-WARR/223132361040?hash=item33f3b9a150:g:rmwAAOSw899bkCCp

Does anyone know where all these recon units come from. Seems odd that there are so many. 

[Motters79]

6 hours ago, mrsmelly said:

This is what I bought from a similar online seller called mp and h. Massive positive feedback. Everything required apart from header tank which cost me about seventy quid. Hasn't missed a beat yet. Fit plenty of big rads they will all get hot. for secondary heating and summer hot water etc has proved a very good buy.

Did you fit it yourself? It also doesn't come with a fuel standpipe. I'm not sure if I need one or if I can use the fuel outlet that used to feed the bubble stove I removed when I bought the boat. It's a third the way down the tank and Has a bigger bore pipe. I could no doubt get an adapter to take the 2mm ID pipe that webasto use, but I don't know if it being lower down the tank would cause extra fuel pressure that might flood the webasto. Has anyobe on here fitted a standpipe? The webasto instructions tell you to go in through the top of the tank but i cant as the top of the tank is outside. I need to go in through the side of the tank where it meets the deck plate of the stern. 

[blackrose]

I might have to change my rads as I've got 4 x singles (60 x 80cm) + a 60 litre calorifier. 

 

I think the rads are about 2000 btu each, plus perhaps the same for the pipework. That's about 3kW plus the calorifier. Is that going to be enough if I only run it for an hour a day with a cold calorifier? 

Edited September 6, 2018 by blackrose

[blackrose]

I'm confused now. I just looked at a 60 x 80cm double convector rad online that said it's only 2300 btu. Are my rads singles or doubles? 

[Boater Sam]

Look like single rads but with rear fins that up the output by about 35% over a plain single, should be fine for your 4kw heater.

[blackrose]

43 minutes ago, Boater Sam said:

Look like single rads but with rear fins that up the output by about 35% over a plain single, should be fine for your 4kw heater.

Thanks. 5kW heater. My rads have heat control valves at the bottom. I think they're just plain gate valves, not thermostatic, but i might be wrong. If I just leave them all fully open will that be OK? 

Edited September 6, 2018 by blackrose

[TheBiscuits]

1 hour ago, Motters79 said:

Did you fit it yourself? It also doesn't come with a fuel standpipe. I'm not sure if I need one or if I can use the fuel outlet that used to feed the bubble stove I removed when I bought the boat. It's a third the way down the tank and Has a bigger bore pipe. I could no doubt get an adapter to take the 2mm ID pipe that webasto use, but I don't know if it being lower down the tank would cause extra fuel pressure that might flood the webasto. Has anyobe on here fitted a standpipe? The webasto instructions tell you to go in through the top of the tank but i cant as the top of the tank is outside. I need to go in through the side of the tank where it meets the deck plate of the stern. 

Mine is tapped off the bottom (ish) of the tank and is fine.  The marine kit is specifically designed for proper boats, and a top sip-tube means you should always have enough diesel left in the tank to get back to shore.

 

If you drink all your diesel into your heater while moored to the bank it doesn't really matter.

[Motters79]

5 minutes ago, TheBiscuits said:

Mine is tapped off the bottom (ish) of the tank and is fine.  The marine kit is specifically designed for proper boats, and a top sip-tube means you should always have enough diesel left in the tank to get back to shore.

 

If you drink all your diesel into your heater while moored to the bank it doesn't really matter.

I get what your saying! I was told (cant remember by who) it was more to do with the extra pressure you get when the is a head of fuel above your tapping point. In my case it would be a 3rd of a tank above the tapping point if the tank were full. 

 

I'm guessing that on the other side of my pre-existing tapping point there is a pipe going down towards the bottom of the tank. Must be otherwise the Bubble stove would conked out once The tank was 2 3rds full. 

[TheBiscuits]

7 minutes ago, Motters79 said:

I was told (cant remember by who) it was more to do with the extra pressure you get when the is a head of fuel above your tapping point.

I think they are talking tripe.  All that you get if you do this is a good supply of diesel to the metering pump that feeds the Webasto.  You can't flood the burner with it in a correctly installed system.

[Cheshire cat]

They look like thermostatic valves to me. Leaving them open will allow the fluid to flow freely. If you get cycling before the boat is warm enough you need bigger radiators. If you don't, you're quids in. 

[blackrose]

13 minutes ago, Cheshire cat said:

They look like thermostatic valves to me. Leaving them open will allow the fluid to flow freely. If you get cycling before the boat is warm enough you need bigger radiators. If you don't, you're quids in. 

How do you know if the heater is cycling? Can you hear it? 

 

I could add another calorifier in the engine room. Do calorifiers have a decent heat output or is a coil insignificant? 

Edited September 6, 2018 by blackrose

[Robbo]

8 hours ago, blackrose said:

How do you know if the heater is cycling? Can you hear it? 

Usually when something is cycling all you can hear is a ding ding, ding ding, ding ding.  

[WotEver]

10 hours ago, Cheshire cat said:

They look like thermostatic valves to me. Leaving them open will allow the fluid to flow freely. 

Or just pull the tops off. Then the valve will be left full open. 

I didn’t know they did this until a service engineer swapped a faulty one at our house. 

[mrsmelly]

13 hours ago, Motters79 said:

Did you fit it yourself? It also doesn't come with a fuel standpipe. I'm not sure if I need one or if I can use the fuel outlet that used to feed the bubble stove I removed when I bought the boat. It's a third the way down the tank and Has a bigger bore pipe. I could no doubt get an adapter to take the 2mm ID pipe that webasto use, but I don't know if it being lower down the tank would cause extra fuel pressure that might flood the webasto. Has anyobe on here fitted a standpipe? The webasto instructions tell you to go in through the top of the tank but i cant as the top of the tank is outside. I need to go in through the side of the tank where it meets the deck plate of the stern. 

I had it fitted by a bloke who knows what he's doing he's fitted loads of them. He adapted the installation I had that was heated by a hurricane heater. He added some big double rads and did a great job. My boat is purpose built live aboard with a dedicated tank for the heating so not ever a problem to do with the engine tank. At the price they are unbeatable.

[Phil Ambrose]

11 hours ago, blackrose said:

How do you know if the heater is cycling? Can you hear it? 

 

I could add another calorifier in the engine room. Do calorifiers have a decent heat output or is a coil insignificant? 

Yes you would hear the unit fire up, run, turn off repeatedly  . Don't see any advantage in adding another Calorifier 

Phil 

[blackrose]

Just that it would add more kW output for the heater to heat to prevent it cycling. I'll only be using it for an hour at a time while my solid fuel stove gets going so once both calorifiers are hot it will be time to switch the Webasto off anyway.

 

 

[Cheshire cat]

Yes, what Phil says. 

 

What I think happens is that the Webasto recognises that the incoming water is not much cooler than the water it is pushing out so it decides to close down. However, the control unit hasn't been switched off as it needs manual human intervention so as soon as the heater has closed down it tells it to wake up again. The cycle takes a couple of minutes or so. 

 

There is a tick tick tick tick but that is just the diesel pump injecting the fuel. I found that noise unacceptable until I unbolted it from the hull.

[blackrose]

9 hours ago, WotEver said:

Or just pull the tops off. Then the valve will be left full open. 

I didn’t know they did this until a service engineer swapped a faulty one at our house. 

I don't think there's much point me pulling the tops off, I'll just leave them fully open. 

[Sea Dog]

1 hour ago, Cheshire cat said:

There is a tick tick tick tick but that is just the diesel pump injecting the fuel. I found that noise unacceptable until I unbolted it from the hull.

Ah, my Eberspacher does that - it's more of a "clonk clonk" which reverberates through the hull and is much noisier than the jet engine sound. I'm concerned how easily detected by submarines this makes me, which is why I can sometimes be seen zig-zagging randomly as I travel along  the cut. 

[TheBiscuits]

13 minutes ago, Sea Dog said:

Ah, my Eberspacher does that - it's more of a "clonk clonk" which reverberates through the hull and is much noisier than the jet engine sound. I'm concerned how easily detected by submarines this makes me, which is why I can sometimes be seen zig-zagging randomly as I travel along  the cut. 

I did wonder when we crossed at that swing bridge

 

[WotEver]

1 hour ago, Sea Dog said:

Ah, my Eberspacher does that - it's more of a "clonk clonk" which reverberates through the hull and is much noisier than the jet engine sound. I'm concerned how easily detected by submarines this makes me, which is why I can sometimes be seen zig-zagging randomly as I travel along  the cut. 

I assumed you’d learnt to boat in a yoghurt pot...

1 hour ago, blackrose said:

I don't think there's much point me pulling the tops off, I'll just leave them fully open. 

As long as they’re not faulty of course

 

The reason the engineer swapped ours was that despite it being permanently turned up full (so why did I fit it in the first place?) it had stuck itself into the minimum position. 

[MtB]

21 minutes ago, WotEver said:

The reason the engineer swapped ours was that despite it being permanently turned up full (so why did I fit it in the first place?) it had stuck itself into the minimum position. 

 

Most of them do this in the fullness of time. 

 

I sometimes wonder if the manufacturers design this feature in deliberately.