Calling David 2552 - D5W advice.

[Gordonmc]

I was going to send a PM to David2452 for some advice but thought that; a. cheeky, b. possibly the subject might help others.
Not that this query is exclusive to Dave2452.
I have an Eberspacher D5W sending hot water to a blown-air matrix and a calorifier. The matrix delivers heat to the aft cabin and heads through two outlets.
That's the system, but it relies on a header tank which is large and occupies a lot of space in a hanging locker.
I seem to remember David describing a sealed system which might mean I can dispense with the header.
1. How does it work?
2. What extra bits of kit would I need?
3. Are there any height or other restrictions.
Thanks in advance.

 

[David2452]

1) it supplies pressure via the potable water system to fill and pressurise the system thus removing the need for the open vent or partly sealed header tank which is less efficient, I would normally place a Spirovent or at least an auto bleed pot in the system at the highest point. The way most domestic CH systems are set up.
2) discard the header and either join the hoses if a recirculated header or blank off if a single pipe system, then fit an expansion vessel which can be anywhere in the system and a filling loop with a pressure gauge, this can be anywhere in the system but the filling loop is best sited close to the inlet side of the circulation pump.
No practical height restrictions at all, the normal 1 bar (cold) used in such systems is equal to having a header tank at the top of a 33 foot mast.

If you would like the marine install manual for coolant based systems which describes and discuisses the various header and pressure fed options with their attendant advantages/disadvantages just drop me a PM with your email.