2kW or 4kW heater?

[Nickdaw]

Do I go for a 2kW or 4kW, my head is spinning trying to decide.
I was always under the impression what will do more will do less, but you can not have more than it can do.
So this is my logic the 4kW will heat up the van quicker so you don’t have to have it on as long.
If you want it nice and toasty a 2kW will have to be running at full for longer, do components wear out quicker at full power for longer?
4kW on for less time to get to the temperature - less use/ware?
I will be getting one of the top 3 sellers but which one I cannot decide its not down to cost I want it to work,
all of them are similar to each other as to what fuel use, power, and output.
I’ve made a little chart to compare, all the info from the maker's websites.

Any info- yes for this one no for that could help me decide.

 

[JOG]

Like the chart....interesting to compare the power consumption v predicted result....suggests the 4kw Eberpacher is the one to go for

 

[RayF]

I would say, in the space of a camper, 2kw will be more than adequate. 4kw will be likely be too much, unless you particularly want it like a sauna.

 

[Martin Gibson]

Hello @Nickdaw ,ours is a webasto but the 2kw is more than enough to have the van hot in no time at all

 

[Higgidav]

Definitely 2kw. Our van is toasty warm in 10mins. 4kw would be overkill.

 

[oldiebut goodie]

Depends upon your envisaged usage and van setup.
I have fitted a 4Kw Webasto Evo40 to my own van which is a LWB with a hightop. I want heating for a quick warm up after dog walking etc in the winter, also I like to shower in a warm room and do not use any heat overnight ( until it gets down to below -10 degrees or so then I might use some heat and shut the window).
If you have a SWB poptop and only want the heater for warmth on summer evening/nights a 2Kw may well suit you best. Don't forget that thin canvas doesn't hold heat in like a hightop.
If you want heat all night, for some bizarre reason, a 2Kw is ideal for running at 0.9Kw for background warmth. A 4Kw is not for this type of usage in these small vans.
I fit Webasto 2Kw heaters in the wheelhouses of small fishing boats where the door is always open so there is plenty of heat from a 2Kw for most scenarios.

OEM fit used to be the Webasto Air Top 3500ST 3.5Kw on the T5 and now is the Eberspacher 4Kw offering for comparison.

 

[boxelder]

You want a low setting of <1kw. The only niggle I have is the ticking of the fuel pump, so which is quietest? I'm told Autoterm now do a silent pump? Do you need time programming? Remote control?

 

[CAB]

2kw with our elevating roof SWB has been fine. 5-10 minutes at full speed then drops to almost silent.

Webasto, and it's inside the van, under driver's seat.

Not done sub-zero, just cold evenings.

 

[Spaghetti]

My concern with a 4KW would be that it’d never be run hard so may suffer from carbon build up, as it does recommend running at a high temp periodically. A 2KW in my SWB is ample down to nearly 0 degrees with the pop top up too.

 

[oldiebut goodie]

Here are some reports on overhauled heaters, you can see the usage patterns in the burning hours and whether the correct heater was fitted:

2Kw ST:
Operating data:
---------------
Working hours...........................................................1719:05 [h:m]
Operating hours.........................................................5000:29 [h:m]
Start count................................................................1021
Burning duration PH 1..33%.................................................5:57 [h:m]
Burning duration PH 34..66%..............................................792:40 [h:m]
Burning duration PH 67..100%.............................................920:28 [h:m]
Burning duration PH >100%..................................................0:00 [h:m]

Operating data:
---------------
Working hours............................................................312:08 [h:m]
Operating hours..........................................................373:19 [h:m]
Start count.................................................................413
Burning duration PH 1..33%.................................................0:05 [h:m]
Burning duration PH 34..66%...............................................29:58 [h:m]
Burning duration PH 67..100%.............................................282:05 [h:m]
Burning duration PH >100%..................................................0:00 [h:m]

Operating data:
---------------
Working hours...........................................................3698:29 [h:m]
Operating hours.........................................................3772:34 [h:m]
Start count.................................................................672
Burning duration PH 1..33%.................................................0:15 [h:m]
Burning duration PH 34..66%..............................................116:18 [h:m]
Burning duration PH 67..100%............................................3581:56 [h:m]
Burning duration PH >100%..................................................0:00 [h:m]


Compare those to a 3.5Kw: ( Looks as though this was over specified for how it was used)

Operating data:
---------------
Operating time at low power range..........................................4600 [h]
Operating time at middle power range.......................................3200 [h]
Operating time at high power range............................................0 [h]
Operating time at boost power range...........................................0 [h]

A 3.9Kw correctly specified:

Operating data:
---------------
Working hours...........................................................5764:19 [h:m]
Operating hours.........................................................8968:04 [h:m]
Start count................................................................2198
Burning duration PH 1..33%................................................34:21 [h:m]
Burning duration PH 34..66%..............................................709:35 [h:m]
Burning duration PH 67..100%............................................5017:45 [h:m]
Burning duration PH >100%..................................................2:38 [h:m]

A 5.5Kw incorrectly specified:

Operating data:
---------------
Working hours...........................................................1773:26 [h:m]
Operating hours.........................................................4518:17 [h:m]
Start count................................................................5951
Burning duration PH 1..33%...............................................905:34 [h:m]
Burning duration PH 34..66%..............................................698:49 [h:m]
Burning duration PH 67..100%.............................................168:57 [h:m]
Burning duration PH >100%..................................................0:06 [h:m]

 

[Spaghetti]

That’s pretty interesting. What make gives that analysis?

Here are some reports on overhauled heaters, you can see the usage patterns in the burning hours and whether the correct heater was fitted:

2Kw ST:
Operating data:
---------------
Working hours...........................................................1719:05 [h:m]
Operating hours.........................................................5000:29 [h:m]
Start count................................................................1021
Burning duration PH 1..33%.................................................5:57 [h:m]
Burning duration PH 34..66%..............................................792:40 [h:m]
Burning duration PH 67..100%.............................................920:28 [h:m]
Burning duration PH >100%..................................................0:00 [h:m]

Operating data:
---------------
Working hours............................................................312:08 [h:m]
Operating hours..........................................................373:19 [h:m]
Start count.................................................................413
Burning duration PH 1..33%.................................................0:05 [h:m]
Burning duration PH 34..66%...............................................29:58 [h:m]
Burning duration PH 67..100%.............................................282:05 [h:m]
Burning duration PH >100%..................................................0:00 [h:m]

Operating data:
---------------
Working hours...........................................................3698:29 [h:m]
Operating hours.........................................................3772:34 [h:m]
Start count.................................................................672
Burning duration PH 1..33%.................................................0:15 [h:m]
Burning duration PH 34..66%..............................................116:18 [h:m]
Burning duration PH 67..100%............................................3581:56 [h:m]
Burning duration PH >100%..................................................0:00 [h:m]


Compare those to a 3.5Kw: ( Looks as though this was over specified for how it was used)

Operating data:
---------------
Operating time at low power range..........................................4600 [h]
Operating time at middle power range.......................................3200 [h]
Operating time at high power range............................................0 [h]
Operating time at boost power range...........................................0 [h]

A 3.9Kw correctly specified:

Operating data:
---------------
Working hours...........................................................5764:19 [h:m]
Operating hours.........................................................8968:04 [h:m]
Start count................................................................2198
Burning duration PH 1..33%................................................34:21 [h:m]
Burning duration PH 34..66%..............................................709:35 [h:m]
Burning duration PH 67..100%............................................5017:45 [h:m]
Burning duration PH >100%..................................................2:38 [h:m]

A 5.5Kw incorrectly specified:

Operating data:
---------------
Working hours...........................................................1773:26 [h:m]
Operating hours.........................................................4518:17 [h:m]
Start count................................................................5951
Burning duration PH 1..33%...............................................905:34 [h:m]
Burning duration PH 34..66%..............................................698:49 [h:m]
Burning duration PH 67..100%.............................................168:57 [h:m]
Burning duration PH >100%..................................................0:06 [h:m]

 

[oldiebut goodie]

Webasto - the only ones that I work on.
Here is some of what I can see on a 2000STC.

 

[rod_vw]

Is there a PC app available to the general public that will access the maintenance port on an Eberspacher Airtronic? Maybe it needs a custom interface ('Eberspacher speak' to USB), if so is such a thing available?

 

[Spaghetti]

Webasto - the only ones that I work on.
Here is some of what I can see on a 2000STC.

View attachment 89840

I have a Webby, and it’s good to know they can be analysed to that degree.

 

[rod_vw]

I have a Webby, and it’s good to know they can be analysed to that degree.

I've seen the huge amount of data from an Eberspacher but as yet haven't found anything available to Joe public that will read it hence above.

 

[oldiebut goodie]

Is there a PC app available to the general public that will access the maintenance port on an Eberspacher Airtronic? Maybe it needs a custom interface ('Eberspacher speak' to USB), if so is such a thing available?

EDiTH was the one for those weird heaters

 

[rod_vw]

EDiTH was the one for those weird heaters

Is the cheaper versions available on eBay any good and worth buying?

 

[Nickdaw]

Here are some reports on overhauled heaters, you can see the usage patterns in the burning hours and whether the correct heater was fitted:

2Kw ST:
Operating data:
---------------
Working hours...........................................................1719:05 [h:m]
Operating hours.........................................................5000:29 [h:m]
Start count................................................................1021
Burning duration PH 1..33%.................................................5:57 [h:m]
Burning duration PH 34..66%..............................................792:40 [h:m]
Burning duration PH 67..100%.............................................920:28 [h:m]
Burning duration PH >100%..................................................0:00 [h:m]

Operating data:
---------------
Working hours............................................................312:08 [h:m]
Operating hours..........................................................373:19 [h:m]
Start count.................................................................413
Burning duration PH 1..33%.................................................0:05 [h:m]
Burning duration PH 34..66%...............................................29:58 [h:m]
Burning duration PH 67..100%.............................................282:05 [h:m]
Burning duration PH >100%..................................................0:00 [h:m]

Operating data:
---------------
Working hours...........................................................3698:29 [h:m]
Operating hours.........................................................3772:34 [h:m]
Start count.................................................................672
Burning duration PH 1..33%.................................................0:15 [h:m]
Burning duration PH 34..66%..............................................116:18 [h:m]
Burning duration PH 67..100%............................................3581:56 [h:m]
Burning duration PH >100%..................................................0:00 [h:m]


Compare those to a 3.5Kw: ( Looks as though this was over specified for how it was used)

Operating data:
---------------
Operating time at low power range..........................................4600 [h]
Operating time at middle power range.......................................3200 [h]
Operating time at high power range............................................0 [h]
Operating time at boost power range...........................................0 [h]

A 3.9Kw correctly specified:

Operating data:
---------------
Working hours...........................................................5764:19 [h:m]
Operating hours.........................................................8968:04 [h:m]
Start count................................................................2198
Burning duration PH 1..33%................................................34:21 [h:m]
Burning duration PH 34..66%..............................................709:35 [h:m]
Burning duration PH 67..100%............................................5017:45 [h:m]
Burning duration PH >100%..................................................2:38 [h:m]

A 5.5Kw incorrectly specified:

Operating data:
---------------
Working hours...........................................................1773:26 [h:m]
Operating hours.........................................................4518:17 [h:m]
Start count................................................................5951
Burning duration PH 1..33%...............................................905:34 [h:m]
Burning duration PH 34..66%..............................................698:49 [h:m]
Burning duration PH 67..100%.............................................168:57 [h:m]
Burning duration PH >100%..................................................0:06 [h:m]

well going off that I would say a 2kW would be more than enough,
thank you @oldiebut goodie

 

[oldiebut goodie]

Is the cheaper versions available on eBay any good and worth buying?

I don't know, provided you can get a connection with the heater and you can run the latest software on the dongle should be OK. ( Software here Download Diagnosis EDiTH Software - Eberspächer ).
All I know is that my official Webasto dongles allow me to run the latest Webasto software which will not run on the knock off dongles.