C/H Header Tank Location

[Dave100456]

2 questions for the plumbing experts:
Diesel heater providing central heating.......
Provided the header tank is the highest point in the heating circuit, does it make a difference if it is located close to or far away from the pump in the flow/return circuit?
Is it better to have the header tank in series in the flow/return ciruit or is it best on a 'T' and thus in parallel on either the flow or return?

 

[smileygirl]

I understand that it is preferable to have it in the return side just before the pump

 

[Dave100456]

Thanks for the quick response.

Do you know why that location is preferable?

 

[philip_stevens]

I take it that you have an Eberspacher Hydronic or similar heater. If so, have a look at the installation instructions downloadable from here

The header tank on our boat is within 3 feet of the Hydronic heater, and above the top height of the highest radiator.

 

[lw395]

From my own flanging about:
It helps if the water header tank is close to the input side of an ebersplutter, so that the pump is fed with water at all times, even if there is air in the system. Pump will scream and unit may shut down if xs air reaches the heater unit.
I put the header tank in series, this worked well, collected all the air, but was prone to making a bit of gurgling/running water sounds. Maybe a tee off to the tank would be better, just make sure its straight up to the tank, so no air gets to the eber. Hope that helps!

 

[Dave100456]

Thanks for the link and info.
I do have a heater that works well but the plumbing circuit needs some tweeking. The rads/ calorifier do not get to working temp (50C +) before the heater shuts down and I believe this is due to poor flow rate. (I have eliminated short circuiting) By changing to a single pipe to the header tank via a 'T' I can reduce the work load on the pump and to the benefit of the circulation circuit.

 

[oxman]

As a domestic plumber I would recommend the following.

on the heating circuit running into the Eber there should be 2 Tees off the main pipe - first must be the breather to top of header then the feed from the header - this means any air coming from the circuit will reach the breather first and bubble up whilst the pump draws from the feed pipe.
I would not recommend a Tee and single feed to/from header because the suction from the pump will reduce the ability for air bubbles to go up to the header.
Best option really is to change to a closed circuit with expansion tank.
To improve flow - all the obvious ways - less elbows - prefer to use bends - larger bore? - how old is the system - does it need flushing - if it has always had air in it then you will have a buildup of sludge - doesnt happen in a closed circuit because there is no oxygen in the water.

 

[searover]

Beeing a heating engineer and gas fitter all my life, i agree with oxman. tell us if you want more info. regards

 

[philip_stevens]

The Eberspacher installation instructions I referred to (above post), show one pipe from the header tank on a two pipe system.

It shows two pipes from the header tank on a one pipe system.

They've been making them long enough, so should know what they are talking about.

 

[Dave100456]

Thanks Oxman and Searover I have pm'd you both and would appreciate a brief chat.

Cheers

Dave