Webasto thermotop servicing with CH

[arcsyst]

Apologies if this has been asked before but I am about to service my webasto following the excellent instructions listed here. However my heater also runs the central heating so I am concerned about not draining down the whole system. I haven't dismantled sufficiently to get to the plumbing yet but there appears to be some kind of isolator valve on one of the pipes. Would this be the normal setup in your experiences?

 

Update: Got access to pipework and it appears that there are no valves, is there any shortcut to draining down?

Edited October 18, 2014 by arcsyst

[smileypete]

If it has a rad cap or the header tank feed and vent are temporarily bunged somehow, it might hold most of the coolant in, try disconnecting slowly with a large tray/dish underneath.

 

cheers, Pete.

~smpt~

Edited October 18, 2014 by smileypete

[arcsyst]

My idea is to shut off all the radiator valves and have a couple of corks handy to plug the pipe where it transits through the engine bulkhead.

 

I'll let you know!

[arcsyst]

That worked well, didn't need the corks, caught about a litre of antifreeze/coolant in a bucket. Now to the workshop to strip down my 4yo heater for its first service!

[smileypete]

[NMEA]

That worked well, didn't need the corks, caught about a litre of antifreeze/coolant in a bucket. Now to the workshop to strip down my 4yo heater for its first service!

Do you have a flue gas anayliser, Thermotop software and interface, otherwise all you will be doing is a decoke, as the guy in the "instruction" did, a proper service consists of quite a bit more. After 4 years my advice would be to replace the burner, scraping off carbon from the evaporator is only a temporary fix and it knocks the burn rate off if you are aggressive.

[arcsyst]

I take your point but it has only run 1500 hrs.

[NMEA]

1500 - 2000 hours is about the time I would be replacing a burner and doing analsis and setup normally.

[raymondh]

Do you have a flue gas anayliser, Thermotop software and interface, otherwise all you will be doing is a decoke, as the guy in the "instruction" did, a proper service consists of quite a bit more. After 4 years my advice would be to replace the burner, scraping off carbon from the evaporator is only a temporary fix and it knocks the burn rate off if you are aggressive.

Mr NMEA,

Do Webasto publish CO figs for a unit ie 90ST running on kerro ? It must? be differente from red/white etc my thoughts are is kerro a cleaner burning fuel?

Regards Ray

[NMEA]

Mr NMEA,

Do Webasto publish CO figs for a unit ie 90ST running on kerro ? It must? be differente from red/white etc my thoughts are is kerro a cleaner burning fuel?

Regards Ray

They don't Ray, but I have found when I have swapped tanks over to paraffin, though mostly on AT series there is little difference in the CO2 and the efficiency remains at about 90% there is no technical reason the T90 should behave differently. I recently stripped an AT5000 that had been running on paraffin for four years, more to have a look than anything as it was behaving perfectly well, there was a little coke but nothing like I would have expected as the Thermotest showed it had run most of it's life at low burn rate being quite a big heater for it's situation which was a welfare unit.

[arcsyst]

They don't Ray, but I have found when I have swapped tanks over to paraffin, though mostly on AT series there is little difference in the CO2 and the efficiency remains at about 90% there is no technical reason the T90 should behave differently. I recently stripped an AT5000 that had been running on paraffin for four years, more to have a look than anything as it was behaving perfectly well, there was a little coke but nothing like I would have expected as the Thermotest showed it had run most of it's life at low burn rate being quite a big heater for it's situation which was a welfare unit.

And you replaced the burner unit I assume?

[NMEA]

And you replaced the burner unit I assume?

No need, unlike one running on diesel it had a clean evaporator with no carbon impregnation so was functioning to specification, had it been running or diesel I would have.

[raymondh]

They don't Ray, but I have found when I have swapped tanks over to paraffin, though mostly on AT series there is little difference in the CO2 and the efficiency remains at about 90% there is no technical reason the T90 should behave differently. I recently stripped an AT5000 that had been running on paraffin for four years, more to have a look than anything as it was behaving perfectly well, there was a little coke but nothing like I would have expected as the Thermotest showed it had run most of it's life at low burn rate being quite a big heater for it's situation which was a welfare unit.

Many thanks, no probs with mine, just user interest and going into another winter

Regards Ray

[NMEA]

Many thanks, no probs with mine, just user interest and going into another winter

Regards Ray

I doubt you will have many problems on the coking front using paraffin, obviously sensor and ECU issues would not alter but those are rare compared to the major problem ares which are in order of frequency in my and every other Webasto agent I knows' experience: coking, inappropriate installs and usage pattern and lack of proper servicing. Though I have to say that since the introduction of ULSD, at least on a properly installed and set up boiler the coking issue is less frequent, in fact I have not had a warranty call out to one of my installs that turned out to be premature coking for quite some time which is very encouraging.

[bigcol]

NMEA If you ever come to MK area, I would indeed be willing to pay for you to come and set up my Webasto heater

Including correcting any instalation issues.

 

I do believe that has been my own short comings on Webasto coking up and other heater problems.

Just ordered a STP carb cleaner for next time I have to decoke.

 

 

Col

Edited October 19, 2014 by bigcol

[NMEA]

Unlikely Col, problem is that besides being a day out of my schedule you would be looking at traveling time of £250 before I even stepped aboard, so it really doesn't make economical sense for most people.