Very poor fibre speed with Billion 7800 & 8200

[#1]

Has anyone got either the Billion 7800N with the OR modem or the 8200N VDSL modem/router working with BT Infinity.?
I've had nothing but trouble for the last month trying to sort this out.
The line constantly syncs @ 2Mbps & Plusnet/BT insist it's "internal wiring" - tosh.
Both boxes are fully capable of PPPoE either using the eWAN port on the 7800 to the OR modem or natively with the 8200.
Why should I be forced to downgrade to an inferior router with the OR modem acting as a replacement for the central heating?
Constructive comments most gratefully received.
Thanks
C

[#2]

Since I don't believe you can get the sync speed from the Openreach modem are you referring to speed test results when linking it to the Billion 7800N
I assume from your disparaging comment about electric heaters that the supplied Plusnet router gives decent speeds so is the problem is the router setup assuming they both used the same cable.
I have assumed that you aren't using BT Infinity but Plusnet Fibre as Infinity is a BT retail product
You can ignore the following as I assume you have already done it.
Does the BT IP profile as given in the BT speed test give a sensible number and not 2000kbps and similarly for the Plusnet Current Line Speed and have you checked the results when wired as opposed to wireless

[#3]

(referred to "BT Infinity" as just the generic fibre offering - they own the wires after all)
BT's performance tester does report the proper speeds (38M/2M) and the 8200 reports the line is operating at the same (my profile appears to be correct).
Already had the OR modem wired to a PC all last weekend & although the speeds were erratic it did seem to stabilise between 20 & 35Mbps - which I put down to contention.
I had work to do on Monday, so the 7800 was reattached & appeared to stabilise at the same (after I'd disabled some Firewall settings - not happy about that) - albeit my latency doubled yesterday morning (@6am) from 20ms to near 40.
No testers appear to show excessive ping times or packet loss (in fact both seem to be miniscule).
The new 8200 was plugged in last night & after initial jumping around was fine until I get up this morning & the damn line is back down at 2 smeg.
There was an engineer logged for Monday, but I've cancelled that as I know for a fact that all that will come from that is that "oh, you're not using the approved boxes, I'm not going to do anything, and here's a bill for the call out" .
I've been with PN for more than 10 years and never had problems 'til now, all the good will they've accrued is rapidly going up in smoke.

[#4]

So have I got this right
Using the Openreach supplied modem you got the correct speeds but bypassing that and using the Billion 8200 you now don't
Since having the lousy speeds have you checked with the Openreach modem rather than just cancelling the visit on the grounds that they will only test with the Openreach modem

[#5]

May be get yourself a cheap OR VDSL modem off Ebay and put hacked software on it such that you can access its web interface 
This will allow you to monitor sync speed and hopefully be able to show whether your problem is on the wiring side or router side...

[#6]

Even using the OR modem it took ages to get things sorted - it would appear that the line assumes that anyone wanting FTTC is only bothered about gaming or downloading "I'm Strictly an X Celebrity on Ice" from iPlayer - those of us who require something a little more complex are left hanging out to dry.
I don't want the OR modem as (1) it's running very hot & (2) yet another plug & set of wires, which was why I went out & bought the 8200 (www.billion.uk.com/product/vdsl/8200n.htm) and Billion even put separate instructions in the box for connecting to a BT VDSL line.
The PN supplied router spec is way below what I require & was in fact never ordered.
The 7800 appeared to work with the OR modem with a few weeks' of messing about, but in the interests of efficiency it was logical to get something that was ostensibly made for the job instead of cobbling together two bits of kit.

Although, what do mean by "checked with the OR modem" ?
Apologies if I'm coming across a bit terse, but I'm getting severely hacked off with the level of support from PN on this issue. The fact that the line was installed on the 4th of November and is still not working properly is not something that engenders a degree of calmness.

[#7]

Do to summarise correctly
After a bit of mucking about the supplied modem works with the Billion 7800N router as you didn't want to use the Plusnet supplied one.
Now you want to use a totally different combined modem/router and because it doesn't work it is somehow Plusnet's fault

[#8]

So, you don't get any speed drops when using the Plusnet-provided router, and leaving that connected for a few days?
If that's the case, then perhaps you need to take this up with Billion, rather than Plusnet.

[#9]

My original request was for anyone with constructive comments regarding getting a Billion 7800 or 8200 working properly with FTTC and whether anyone had similar issues.
A ticket has been raised with Billion, my gripe with PN is that all they can come up with is "internal wiring" at fault and can't (nor would expect them to) provide detailed support for the 7800 or 8200 which happen to be vastly superior bits of kit to that supplied by default.

[#10]

Do you see 2Mbps sync speeds with the OR modem and the 7800N acting as router?
Certainly the choice of router (Plusnet's own, a Billion, or a PC connected directly) shouldn't have any impact on the sync speed whatsoever. The modem should sync even without a router connected at all.

[#11]

I have no trouble with my Billion 7800N and the BT Openreach modem. It is completely capable of a full speed fibre connection.
So let's clear up a couple of things.
What firmware are you running? 1.06d is certainly good enough; anything earlier and you could consider updating.
There should be (almost) no internal wiring. You are using fibre and you should be connected directly to the master socket. You could try a different cable between the modem and master socket.
Presumably Plusnet supplied you with a router when you went for fibre. How fast does that go?
(As you have already tried two routers, albeit both Billions, it seems unlikely to be a router problem to me)
(Just in case, let's be clear that Plusnet fibre is a 40Mb down, 2Mb up package. But I don't think you have download and upload confused)