I've had my Aurora over a year now (original post here) during which time I've done it up. The usual things descale, new seals new paint, new spring, the boiler has been insulated with 1/2" foam.
It is basically the same as this so I would expect similar results reported on the thread, I linked to this particular machine because mine has the same type of HX, a horseshoe shaped pipe entering and exiting through the end plate with a external pipe to a chamber welded to the boiler, the group is attached to this chamber. Later Auroras have a HX pipe going up through the boiler directly into the back of the chamber I expect these to be more efficient anyway that type has a different HX setup.
Problem is getting the brew temp hot enough. Ive tried different p/stat settings from 0.9 to 1.6 bar. I've tried pumping up the group temp by retaining the old puck and pumping water through it.
I have a couple of OE thermal strips fitted, one on the front of the group and one on the neck, I originally thought they were faulty, they're not, it's just a battle getting the group hot enough for a reading.
I took a reading with a t/c bead on top of a old puck, it's just a cheap chinese t/c, previously I tested some boiling water, it was at least bubbling in the pot, recording a temp of 96-97 celsius so I expect it is reading 3 or 4 degrees cool.
Using a old puck I took some readings pumping up the temp{no flush) the following temps are all celsius
1st pull 80
2nd pull 80
3rd pull 76
4th pull 80
5th pull 80, neck temp 90
6th pull 82
7th pull 84, neck temp 95
8th pull 86, neck temp 95, group temp 90
9th pull 85
10th pull 87
waited 45 seconds to ensure the boiler had recovered and recorded a final temp of 89
3or 4 degrees needs to be added to these results to allow for the offset.
Using a old puck is not ideal as the water tends to flow to freely so I held back on the lever to slow it down a bit.
I need to get the brew temp up somehow any suggestions maybe a more conductive gasket material may help, currently I have tried gaskets made from Alimen and I think Klingerite both are thick materials.

PS: I measured the temps of the of the internal chamber and the group flange
chamber 95 celsius
flange 80 celsius
once again allow for offset
So theres quite a temp drop between the two, which makes me wonder if a more heat conductive gasket could help.

On an Aurora Termozona which I worked on and played with in situ, there was the same problem of too cold group and we solved this by reducing the water line pressure with a regulator to about 1bar. The hx is fairly small volume and the logic was to slow the flow through the hx. The group actually rapidly cooled rapidly when flushing before the line pressure fix. I thought of the gasket material but after modulating the line flow even Teflon was ok.

Thanks Doug, I have one of your line pressure reguators currently set at 1.5 bar, also I bought from yourselves a Astoria backflow valve which I have fitted to a custom made holder as a flow control valve. A problem I have found with increased pressurestat settings is the increase of pressure inside the HX, the water can't expand as in a boiler so the HX pressure builds up resulting in a puck destroying surge,(that's my thinking on it right or wrong) the flow control valve was made to overcome the surge problem. I will reset the line pressure to 1 bar and see what happens.

Hi Ted, as you know my Brugnetti was the later style HX, so i never had this problem.Here's a few suggestions;

-Have you checked the HX pipes for scale or anything else blocking the flow/thermal transfer?

-Possibly insulate the HX pipe from boiler to groupneck, and also the groupneck area with a flexible insulation like insulbrite

-As mentioned a thinner/more conductive gasket may help.From memory mine was a thin 1 or 2mm card material, similar to klingersil mtl

Good luck
Mike

Hello Mike
Pipes have been descaled there is no obstruction.
Pipe from HX to group mount plus the mount chamber itself have been wrapped with insubrite already, also the group itsef has been wrapped with insulbrite.
The group gasket is quite thick I could make a thinner one to try.
Trying Doug's suggestion at the moment giving that a go.
Ted

I've tried a few different things, reducing the line pressure, removed the 1/2" foam boiler insulation, removed the top group cover but I still need to get more heat into the group i would like to try a more heat conductive group gasket any suggestions of a suitable material and supplier?