Webasto Dual Top Evo installation problem

[drudru]

I am installing a Webasto Dual Top Evo, to heat air and water. The device can automatically flush the water if it detect frost. In order to do so, the water must be replaced by air. The installation instructions state that a vent on the plumbing is needed, and that vent needs to be higher than the vehicle water tank.

My problem is this. What do I use to vent pipes that can be pressurized by the water pump? Flushing pipes manually is simple, just open a sink faucet, open flushing valve, gravity takes care of it, water goes in the faucet to replace water. But when it is done automatic, the faucet is obviously not open. My internet search keep bringing up vents for grey and black water pipes, which are installed over the pipe, in non-pressurized pipe

I looked at 2 check valves. On one model, I could not conceive that it would prevent water from passing through for at least a moment before closing the small "door". On the other model, I tried blowing air in it with all my lung power, and air wasn't going through.

Anyone here has done this installation? Anyone know the solution to my problem?

 

[SkiFreak]

I would have thought that contacting your local Webasto distributor/installer might be beneficial, as they should know how to install their own products.

 

[drudru]

Unfortunately the distributer/installer has never done a Dualtop. They install airtop and thermo tops all day. But they mainly do semi trucks. It is the only webasto dealer in my area.

 

[gait]

Maybe just me. I can't conceive of anything other than a solenoid operated or motorised valve for venting pressurised pipe. Whether there is a signal available from the Webasto I have no idea. If there isn't I would call it a design flaw.

In Aus I've found the Webasto technical help usually offer sensible answers. They seem to be capable of saying "don't know but will find out" which is gold in these days of recalcitrant dealers and scripted call centres. Contactable through their website http://www.webasto.com/au/

 

[dlh62c]

I'm sorry that I can't be much help. But I have a couple of questions.

Can you post some pictures on the installation?

Can the heater run while under way or do you have to be parked?

 

[drudru]

I'm sorry that I can't be much help. But I have a couple of questions.

Can you post some pictures on the installation?

Can the heater run while under way or do you have to be parked?

Not much could be seen from pictures, it is installed in a "busy" spot with lots of other things around. Yes the heater is diesel and can run when parked.

 

[DzlToy]

Whether the dealer is local to you or not, should be irrelevant. Find one who is familiar with the product and ring them up. Often times the person answering the phone is useless, so ask for tech support or to speak with an installer. If you have a very specific technical question, the phone answerer will be baffled and put you through.

Something like, "I am in need of a heat cured cyanopoxy adhesive to bond polyisocyanurate insulation to extruded polystyrene foam and Ultra High Molecular Weight Polyethylene panels" usually does the trick

Make something up if you must, I just did....

 

[drudru]

Whether the dealer is local to you or not, should be irrelevant. Find one who is familiar with the product and ring them up. Often times the person answering the phone is useless, so ask for tech support or to speak with an installer. If you have a very specific technical question, the phone answerer will be baffled and put you through.

Something like, "I am in need of a heat cured cyanopoxy adhesive to bond polyisocyanurate insulation to extruded polystyrene foam and Ultra High Molecular Weight Polyethylene panels" usually does the trick

Make something up if you must, I just did....

No worries, I won't google it
I wrote to webasto Australia, got a useless answer. I wrote to webasto USA, still waiting on a reply.

Someone mentionned an Inline check valve like a Sharkbite, which uses a ball instead of a "door". I might just test it out, see what it does.