webasto installation for heating only

[spacepidgeon]

Hi all

first time poster so apologies if this has been answered before - I caouldnt seem to find the info I need...

 

I am about to install a webasto thermo 90s on our boat with 5 large radiators - this is not being connected to the engine, so it will just be for heating... I could really use some of the forum's expertise or experience before I put it all in.

 

The plan is to install the rads in a parallel configuration using 22m plastic barrier pipe under the floor and 15mm pipe to the rads

I imagine that rubber hose should be used to connect the heater to the pipes

Is it OK for me to have the heater above floor level in the engine room?

I was thinking to also use a small expansion tank - is this necessary and where exactly should it go?

What about 1-way check valves or valves for bleeding?

Is there anything else I am missing?

 

Thanks in advance for any help you can give me!

 

Cheers marc

[granddad]

22mm is good, 15mm to the taps there is no other way. Rubber hose to the inlet and out let both ok. The first metre outlet after the rubber should be 22 mm copper as it gets very hot. The 90s is pumped so no gravity feed and all pumped. Put the webasto on the swim and drop the feed and return into the engine room bilge and on to the radiators.

The 5 radiators must be at least 10kw output or the 90s is too big and will go to idle too quickly and choke up with carbon. If you can connect the calorifier to the webasto you should as it will then heat the second calorifier coil and pre heat your engine with less engine wear and easier start up. Also it will give you more load on the webasto and act like an extra radiator.

You need a header tank ie open to atmosphere, the expansion tank is good if you have a pressurised system. If it's presurised the rads are hotter but you need a accumulator to steady the pressures and to be pumped up for those pressures. I never bothered, it was hot enough.

I have removed my webasto 90s boiler as it seemed to need white diesel and after red diesel it wouldn't fire up, no one was sure why. I'm fitting a webasto 2010 with a different lighting system as I have no room for a white diesel tank. If you want to buy the old system u r welcome.

best of luck

ken

[spacepidgeon]

Hi again

Well I am kind of stuck with the 90S as its all I have - the radiator total output is around 7kW I think (6x 4400 BTU)

 

Can you explain what you mean by 'Put the webasto on the swim' Do you mean the webasto has to be at water level?

Also what do you mean by 'drop into the bilge'? Do you mean I should route the pipes into the bilge water? for extra cooling?

 

As I said I would like to keep the webasto on the side of the hull if possible?

 

Finally - should the header tank go on the cold or hot water side, and does it need one or 2 connections?

 

I have heard about possible problems with red diesel but was told using a proper filter should take care of it.

 

Thanks Ken, All the best!

Cheers marc

[OldGoat]

Hi again

Well I am kind of stuck with the 90S as its all I have - the radiator total output is around 7kW I think (6x 4400 BTU)

 

Can you explain what you mean by 'Put the webasto on the swim' Do you mean the webasto has to be at water level?

Also what do you mean by 'drop into the bilge'? Do you mean I should route the pipes into the bilge water? for extra cooling?

 

The Swim is the flat bit in the engine room on what is known as the uxster plate - it resolves the hull at water level where the side plate sweeps round to where the propellor is - well it dows on a narrowboat. He's suggesting to put the unit there as it's othewise useless space and it's best to have the unit near the fuel supply an keep iot away from the cabin as they make sone noise.

Similarly, you've got to run the pipes down tow to get them below the floor, though I wouldn't (for choice) run them in the bilges - which eievitably get muc and water in them.

 

As I said I would like to keep the webasto on the side of the hull if possible?

 

You could mount it anywhere - I've seen them in a cupboard - but that wastes storage space - hence the suggestion above

Finally - should the header tank go on the cold or hot water side, and does it need one or 2 connections?

 

There was a thread here recently where two pipes were suggested to stop airlocks - sounds a bit overcomplicated to me - but it wouldn't do any harm. Otherwise probably on the return side (cooler and lower pressure) is better.

I have heard about possible problems with red diesel but was told using a proper filter should take care of it.

 

The boiler being a pressure jet has small orifices in it which could be blocked by dirty fuel and it's reported that Ebespacher units do have problems with Red Diesel, but there's little information of how / what / why / when. Webasto and Mikuni units are less prone to any problems - provided that you follow the installation instructions pretty well to the letter if you haven't got any then look at the Mikuni site for their version (the units are similar in principle). I have my Mikuni fed from a T off the engine feed (much frowned on by sea going boats bacause of possible pressure drop), so the fuel is pre-filltered AND there's another finer filter just before the solenoid pump.

 

Thanks Ken, All the best!

Cheers marc

[spacepidgeon]

OK thanks oldgoat - really helps to clear a few things up. I should have mentioned its a dutch barge so no shortage of space in the engine room.

 

I will follow an installation something like this (see image) - teeing off the main diesel tank

 

Two (or three) more questions -

#1 the webasto installation instructions say the webasto should be no more than 20cm below the top of the diesel tank - how critical is this and why is this recommended? I was hoping to put it a bit lower

#2 Is copper piping (5mm) or rubber tubing prefereable for teeing off the diesel? I already have a genny and the engine running off the same pipe - can this cause problems?

#3 in the config shown in the image - do you think i will need any extra valves to bleed air out of the system or does the header tank take care of it?

 

Great forum and thanks for your help - hope I can help someone else along the line!

[NMEA]

If you PM me an email address I will send you a PDF of the official marine Thermo 90s factory installers manual (not service manual or vehicle install), it will answer all of your questions and probably many you haven't even thought of and includes types of circulation, discusses the three types of header tanks with advantages and disadvantages, pressurised systems etc as well as basic unit install and fuel supply..

Edited December 28, 2012 by NMEA

[NMEA]

 

#1 the webasto installation instructions say the webasto should be no more than 20cm below the top of the diesel tank - how critical is this and why is this recommended? I was hoping to put it a bit lower

#2 Is copper piping (5mm) or rubber tubing prefereable for teeing off the diesel? I already have a genny and the engine running off the same pipe - can this cause problems?

#3 in the config shown in the image - do you think i will need any extra valves to bleed air out of the system or does the header tank take care of it?

 

1) No reason not to really, but you may need a solenoid shut off valve operated by the 90s if it does cause issues, the reason for the stipulation is to prevent syphoning and or exess fuel delivery but as the dosing pump is a solenoid pump it also acts as a shut off when not pumping so you may get away with it, fit the pump as close as practical to the tank.

 

2) Wrong on almost every level, never Tee a fuel take off, always use the proper stand pipe as a dedicated supply for the heater, 5mm copper pipe is too large and can cause bubbling and flame outs, 2mm bore copper or S/S tube is the thing to use with BS7840 short rubber connections between the pump and copper also heater nipple, form the ends of the copper where it enters the rubber tubing.

 

3) the config you show is the most basic and inefficient of all for the bleeding of air and on going reliability but all this is explained in the dedicated marine install document I offered above.

 

One of the most important things with an amateur install is to have a Webasto tech with the right kit and training to come and check / adjust the exhaust CO2 output which relates to the cleanliness of the burn and why most people who don't have it done complain about premature sootting and coking up down the line.

[granddad]

Two (or three) more questions -

#1 the webasto installation instructions say the webasto should be no more than 20cm below the top of the diesel tank - how critical is this and why is this recommended? I was hoping to put it a bit lower

#2 Is copper piping (5mm) or rubber tubing prefereable for teeing off the diesel? I already have a genny and the engine running off the same pipe - can this cause problems?

#3 in the config shown in the image - do you think i will need any extra valves to bleed air out of the system or does the header tank take care of it?

 

q1

my webasto was on the swim and so was the fuel tank bottom. The crown of the fuel tank was 15 inches above the webasto feed. But none of that made any difference and it worked well for 12 years. There were two filters one in the dosing pump and one on the line. As I say it worked fine on white diesel but failed to start on the main fuel tank when it had for years previously.

 

I wish I could have tested my red fuel for "set fire ability" if that's a word (volatility?). The main engine uses that fuel no probs. The system worked well in previous years, improved with the ULSD of 3 years ago, I got some old diesel at st johns in lechlade last summer then put in a new feed line into the tank, maybe the end of the pipe was too near the bottom of the tank and water was collecting there. I polished the fuel but it still wouldn't start. The filters didn't clog up, I had twin 90s's and swapped them as they failed. The burner trays were renewed/cleaned each time. But still it worked on the test bench and not in situ. It must be my installation or fuel but why did it work previously and not now?

 

q2

its not good practice to tee off the main engine fuel line - why bugger up a perfectly good configuration on the main engine - but then you will have to tap the main fuel tank and drop in a feed pipe for the webasto. Either drill a big hole and offer up a bulkhead fitting or drill and tap a 1/4 British standard pipe fitting. Don't use webasto pipe its 4.6 od and expensive - a 1/4 bsp fitting will take 6mm brake pipe which is cheaper and more available. Rubber piping could be a fire hazard perhaps.

q3

The header tank is filled to say 2 foot above the webasto nothing running. Now bleed the air out of the top of the webasto then proceed around the rads and bleed the air in the usual way from the top of the radiators - while keeping the header topped up. Start it up and bleed the radiators again.

 

Contrary to what is said above the 90s is not a pressurised fuel system it is a drip feed (dosed) system - however filters are important to keep the bits out.

 

Its good to see someone trying stuff for themselves - so good luck to you.

 

Ken

[NMEA]

Contrary to what is said above the 90s is not a pressurised fuel system it is a drip feed (dosed) system - however filters are important to keep the bits out.Ken

 

Actually you are both wrong, it is not true pressure,i.e. pressurised jet and nor is it drip feed, the dosing pump feeds the fuel under pressure to the evaporator where it disperses in the sintered material, evaporates, mixes with the forced air provided by the blower motor and burns.

[Chalky]

If you do have to have a header tank plumbed in the way you show arrange for the T to be on its side with the top stick of the T vertical. The flow should come in through what would have been the down leg on the T and exit vertically downwards. The upwards leg of the T should go into the expansion tank. This design will cause the fluid flow to temporarily stall and make it easier to de-gas. Ideally you want an arrangement where the fluid flows through the header tank which is standard automotive practice.

Edited December 28, 2012 by Chalky

[spacepidgeon]

If you PM me an email address I will send you a PDF of the official marine Thermo 90s factory installers manual (not service manual or vehicle install), it will answer all of your questions and probably many you haven't even thought of and includes types of circulation, discusses the three types of header tanks with advantages and disadvantages, pressurised systems etc as well as basic unit install and fuel supply..

 

hi thanks but i dont have any ability to PM on this forum??

please email me using mrea at ic d0t ac d0t uk

cheers

[Grace and Favour]

hi thanks but i dont have any ability to PM on this forum??

please email me using mrea at ic d0t ac d0t uk

cheers

 

Yo0u need to have made at least 5 posts on the forum, and then you will have pm facilities. . .

 

(Reply to this - you'll be there!!!)

[NMEA]

hi thanks but i dont have any ability to PM on this forum??

please email me using mrea at ic d0t ac d0t uk

cheers

 

Sorry for the delay, I was travelling yesterday, have sent at 09:30 30/12/2012 (along with copies to a few others that requested it) and hope I interpreted your anti bot email address typing correctly, let me know if it doesn't arrive for any reason all those that asked.

Edited December 30, 2012 by NMEA

[smileypete]

I wish I could have tested my red fuel for "set fire ability" if that's a word (volatility?). The main engine uses that fuel no probs. The system worked well in previous years, improved with the ULSD of 3 years ago, I got some old diesel at st johns in lechlade last summer then put in a new feed line into the tank, maybe the end of the pipe was too near the bottom of the tank and water was collecting there. I polished the fuel but it still wouldn't start. The filters didn't clog up, I had twin 90s's and swapped them as they failed. The burner trays were renewed/cleaned each time. But still it worked on the test bench and not in situ. It must be my installation or fuel but why did it work previously and not now?

The flammability of diesel is it's 'cetane' (worth a google). There's different 'cetane booster' chemicals that can raise this number, but whether they would help reduce these heaters coking up in all cases is another matter.

 

When you say it worked on the bench but not in situ, was that working on the bench with red diesel and without the normal intake/exhaust fitted? If so, maybe the reduced airflow through the intake/exhaust can make the mix too rich with red diesel for the heater to work properly. As NMEA says, the mixture can be adjusted by a Webasto technician, ISTR someone saying there's a fan speed 'profile' that can be adjusted.

 

Something that might be worth a try is getting an extra pump so that the heater can be started on paraffin or some witches brew then switched over to normal diesel, just by switching from one pump to the other and having both feeds tee together just before the heater. Something like a timer relay and/or a thermal switch could be used to control the switching. OK an extra fuel pump is £60-80 but if it reduces the coking up and helps reliability it could be worth it.

 

cheers, Pete.

~smpt~

Edited December 30, 2012 by smileypete

[NMEA]

I wish I could have tested my red fuel for "set fire ability" if that's a word (volatility?). The main engine uses that fuel no probs. The system worked well in previous years, improved with the ULSD of 3 years ago, I got some old diesel at st johns in lechlade last summer then put in a new feed line into the tank, maybe the end of the pipe was too near the bottom of the tank and water was collecting there. I polished the fuel but it still wouldn't start. The filters didn't clog up, I had twin 90s's and swapped them as they failed. The burner trays were renewed/cleaned each time. But still it worked on the test bench and not in situ. It must be my installation or fuel but why did it work previously and not now?

Ken

Ken, I very much doubt that fuel quality is the issue with your non start as there is no mention of clouds of white smoke, if there are then read no further.

Poor fuel of even the worst quality will still be evaporated by the glow pin and produce clouds of white smoke (unburned diesel) even if it does not ignite, in my years dealing with these things on a day in day out basis purely on marine applications I have never known otherwise if the issue is fuel quality pure and simple with no other faults on the system, so without wishing to teach granny to suck eggs I make the following suggestions / questions.

Have you successfully bled the fuel right through to the heater connection, this can be a bit difficult to achieve for certain on inland boats due to the BSS requirement for solid pipe, so, remove the rubber connection between the pipe and the heater and pop a short length of clear tube so you can see when you have bubble free fuel. To more easily bleed do not rely on the heater to give the pulses to the pump but use a length of twin cable with an on off switch connected to the battery and provide the pulses yourself by flicking it on and off or pressing if it is a button type.

If you are unable to bleed it to solid fuel in the clear tube then look to a blockage, see if you can blow back from the tank side of the pump, and similarly in the pump to heater length. Check all connections are air tight, it is not unusual to have a situation where although no diesel leaks due to the low pressures involved air can be drawn in making full bleeding impossible this goes for all compression fittings flexible tube/copper interfaces and filter seals. Are you using the same pump on the bench as in the vessel? is the length of the fuel delivery mirrored on the bench and vessel?

If all the above checks out OK then use a multi meter to check the voltage at the heater whilst it is in start up mode and observe the readings throughout the full start up cycle and ensure it is getting what it needs, no use just checking it any other way as it is possible to get volts without amps due to loose or corroded cables and terminals and it needs both V & A, as do all things that work by electrickery. One final thing, an in a way I hessitate to mention it, you say you fitted a new fuel take off, I would take a close look at that, possibly even reverting to the origonal one for a trial.

Edited December 31, 2012 by NMEA

[NMEA]

As NMEA says, the mixture can be adjusted by a Webasto technician, ISTR someone saying there's a fan speed 'profile' that can be adjusted.

cheers, Pete.

~smpt~

 

 

Unfortunately there is a great deal of misinformation floating about on this subject, it is not a simple matter of fan speed, firstly one must start from a datum and this is always fuel delivery rate, this being the parameter that defines the heater output. From that datum there are many ways of adjusting the air volume to achieve the required CO2 level which include but are not limited to: a simple air bleed screw as for instance on the heater which is the subject of this post through fan speed adjustment via potentiometers on open board ECUs through adjustments that can only be made via programming the ECU with Webasto (or other manufacturers) diagnostic software and interface through to quite complex and bench performed shimming of the air motor. Of course it is possible to match the air to the fuel delivery even if the fuel delivery is not to spec and whilst this will produce a clean burn, without first checking and if need be adjusting the fuel the unit will not be giving full heat or worse, if the fuel delivery is too high and you adjust for a clean burn the unit will be operating at temperatures higher than designed for and possibly overheat or continue to operate at a temperature just below overheat shut off and reduce plug, burner life and possibly damage other components.

Edited December 31, 2012 by NMEA

[granddad]

Thanks for your thoughts but - On the 90s I had a switch over valve and started on white, ran on red and shut down on white. If I stayed on white it was ok but I don't want another fuel tank.

Its not the installation as 1) it ran for years on red 2)the guys on utube are running them blocked up on a couple of bricks not much installation there.

ken

[Sean & Coral]

If you PM me an email address I will send you a PDF of the official marine Thermo 90s factory installers manual (not service manual or vehicle install), it will answer all of your questions and probably many you haven't even thought of and includes types of circulation, discusses the three types of header tanks with advantages and disadvantages, pressurised systems etc as well as basic unit install and fuel supply..

 

NMEA - would you be prepared to email the same document to me please? I'm about to commence the install of my widebeam and have the Thermo 90S as well. A bit cheeky of me I know, but it would be extremely useful.

[NMEA]

[quote name='Sean & Coral' timestamp='1360932160' post='1026924'

NMEA - would you be prepared to email the same document to me please? I'm about to commence the install of my widebeam and have the Thermo 90S as well. A bit cheeky of me I know, but it would be extremely useful.

 

Hardly cheeky, I'm happy to do it, just PM me an email address, do you want the T90S workshop manual as well as the marine install document.

[Sean & Coral]

Hardly cheeky, I'm happy to do it, just PM me an email address, do you want the T90S workshop manual as well as the marine install document.

 

 

PM sent NMEA, and many thanks! Yes to to the offer of the workshop manual as well.....

 

Yours Aye

 

Sean

[NMEA]

PM sent NMEA, and many thanks! Yes to to the offer of the workshop manual as well.....

 

Yours Aye

 

Sean

 

Both sent to the email in the PM,let me know if they arrive OK.

[Orca]

Thanks for your thoughts but - On the 90s I had a switch over valve and started on white, ran on red and shut down on white. If I stayed on white it was ok but I don't want another fuel tank.

Its not the installation as 1) it ran for years on red 2)the guys on utube are running them blocked up on a couple of bricks not much installation there.

ken

My findings thus far: Having purchased both your 90S units from you - I have managed to get one unit firing on the kero/diesel mix I use, using the older (and well used burner cartridges) that had a different 'webbing' material. Using the newer cartridge you bought (on one unit) it won't fire. The second unit I have not yet tried. This is in synch with the problems I had on my own two Thermo 90 units - both working well until I purchased newer (designed for the ST unit??) cartridges that had different material for fuel dispersal/evaporation. They work - albeit sporadically (in my experience) but poor reliability. The older cartridges fire up without question, time after time (and they are ((imo)) near life expired. I wil report as I go on what I find.

[NMEA]

Using the newer cartridge you bought (on one unit) it won't fire. The second unit I have not yet tried.

These did not come from Turkey did they?

[Orca]

These did not come from Turkey did they?

I've no idea as I bought them off Ken (granddad) a few weeks back and the burner cartridges were almost like new (as Ken had stated to me). I do not think they are Turkey parts though.

 

For one of my own Thermo 90 units I purchased a brand new burner cartridge in late 2011 (not from Turkey). When I got it, I noted the gauze/webbing was not quite so compressed and of a different material than the older ones I'd got (about 8 of them in varying condition). When I put the new one in, it took 6 or 7 attempts to get it to go initially. It lasted about a month or so, before sporadically flaming out or non-starting, though sometimes it would be fine and fire up no trouble at all. At that point I got hacked off with the idiosyncracies of the thing and put one of my older cartridges back in and it was fine. I have been using them ever since.

 

Then, about a month or so ago, I decided to try that new/hardly used one I bought in 2011. I put it in and the unit wouldn't fire. Put the old one back in - no problem, fired up ok. That cartridge had done about 40-50 starts and it hadn't worked since. I noticed the cartridges that came in the 90S units I bought from Ken were similar.

Edited March 9, 2014 by Orca

[NMEA]

Interesting, I ask because there have been some non Webasto burners and burner inserts on the market which are pretty poor quality, a few other parts too, Webasto tested them objectively and found them lacking in a number of areas.