Hydronic heat

[somewhereinusa]

Originally Posted by Booyah45828

WOW! What a system this is. Probably one of the best ones I've seen designed. I love it.

Do you have a picture of the heat exchanger setups, or a link to what you used?

Is your heat exchanger for the engine coolant to mail loop protected by a thermostat in case the engine coolant goes above the rating of the pex?

Heat exchanger is one of these, not this one but something similar, https://www.amazon.com/Brazed-Exchan...0644900&sr=8-5

There isn't a water pump as such for the water heater. I have a switch that can turn on the pump that is inside the Espar. Osmosis seems to work well enough.

[DrDanger]

Starting to put my Webasto together to do a bench test

I am trying to figure out how to wire the DP30 fuel pump. This is sold without the plug wired to allow you to trim to length and then finish the terminations. The problem is I am not sure how to wire it (which wire connects to which terminal on the pump). I did a bit of googling, but the best answer I could come up with is a pigtail that shows where the blue wire goes (this is the signal wire from the Webasto). Would it matter if I hooked it up backwards? (i.e. would it damage the pump?)

[DrDanger]

I finally finished the system this past spring but didn't get to really test it out until now. We moved into the bus full time last week and I am afraid to say my hydronic system has been disappointing. We have been in some 25-35F weather at night in the mountains of WV and it only kept the bus up around 50-55F. I have a Webasto Thermo Top C which puts out 17K BTUs (about half of what somewhereintheusa has) and the PEX is under 3/4in OSB plywood and LVP flooring. Is this the best I can expect or is there something wrong with my Webasto? I don't have any temp gauges installed on my manifold, but the return line get pretty darn hot (we spent hours and hours getting the air out of all of the loops, but I don't think that is the issue. I left the vast majority of my terrible, drafty bus windows so that isn't helping. If anybody has any other things to check I am all ears.



I didn't include any radiators to blow hot air, a decision I regret now. I think we'll get by this winter without, but if we are still in the bus next winter I am really considering tapping into the PEX to install one or two.

[cadillackid]

The return line being really hot means you have good flow .. could also mean you aren’t pulling much heat off of the loops. … the webasto 17 will keep the water 165-170 and throttles down when it is near that. If your webasto is running full blast all the time then you just need more heat. If it is slowing down or cycling off then you need to pull more heat off the pipes.. use a bus heater or 2 to pull more heat off.

50-55 would be bundled up and miserable for me …

[DrDanger]

It does cycle on and off so that confirms your suspicion that I have enough heat (or at least I have more potential heat) that is not being put into the bus. Now it is time to research radiators/blowers... Thanks!

[somewhereinusa]

Did you use any kind of metal heat exchanger plate on the in floor piping?

[DrDanger]

Originally Posted by somewhereinusa

Did you use any kind of metal heat exchanger plate on the in floor piping?

Yes, I used aluminum heat exchanger plates everywhere I could (not around bends obviously).