Frequency Signal Solutions Reviews 

I've been using the Cel Fi PRO for over a year now and for the most part it works but there have been a few issues.
I have a three story house with the Window Unit installed on the top floor where I can get three bars of O2 reception. With the Coverage Unit on the ground floor in the lounge, it only seems to be transmitting two bars (which is what the phone shows also). Phone calls can be a bit sketchy where a lot of the time, the person on the other end can't hear me properly.
I tried moving the CU to the kitchen to increase the range as it wouldn't be directly below the WU. This initially gave out full reception but in doing so, completely killed my Sky Q service where the mini boxes around the house are all linked via 5Ghz. Apparently the Cel Fi PRO should adjust it's frequency so as not to interfere but after a Sky engineer spent five hours trying to unsuccessfully link the mini boxes, we discovered that by turning off the Cel Fi PRO, everything else worked instantly. It also stopped me linking a wireless SONOS sound system and Powerline plugs that also extend your WiFi.
I'd previously tried to update the Cel Fi PRO firmware by plugging in the CU to a computer. The computer would never recognise it and the iPhone app needed it to be updated before that would work too. Then two weeks ago, on the verge of giving up, I tried connecting it again and this time it successfully updated the firmware. Both the app and the computer version can now see the Cel Fi PRO and show what channels are being boosted and by how much.
I tried a different position for the CU in the kitchen and I now have full reception on my phone and perfect call quality. Sky Q had been behaving better recently (before the update) and not loosing picture as before so I don't know whether it was the Cel Fi update or a Sky update or a combination of both that is allowing everything to work harmoniously now.
However, the cell reception on the middle floor is still around two bars which seems strange as I was under the impression that the two units created a bubble of coverage and the middle should be the prime location. It seems as though you're better of standing near to the CU to get the best strength.
Without the units installed, phone coverage is barely one to two bars with very slow internet and very patchy call quality due to the foil in my well insulated walls so it's essential that the Cel Fi PRO does it's job well, especially at £699 which I paid in June 2016.
A few months ago I had tried contacting the UK company where I purchased it from for assistance and to see if they were aware of the conflict with the Sky Q mini boxes. Unfortunately no emails were replied to and no one ever answered the phone.

I had good advice from them initially over e-mail, but contact via telephone was difficult. I'm not sure where they are actually based. The first unit didn't work well so they upgraded me to a higher end unit, on the basis that I could return the items it this didn't work. It didn't.
When I then tried to return the items I had great difficulty and in the end had to get the credit card company involved.

Very easy to set up and works faultlessly. Boosts a 1 bar signal to 5 bars throughout the house

The only downside is the price which is eye watering.

The units don't work despite some helpful people speaking to us from Cel-Fi we couldn't get them syncing to each other. It turned out an expensive mistake as we ended up buying a ee signal box for a fraction of the cost. Our Cel-Fi is sitting in a draw unused!

Very patchy in its performance. Could be the supplier signal, could be the weather, but no idea as the diagnostics are none existent.

spent £800 for the best booster for o2 - apparently... system didn't work as intended and after calling multiple times for support and guided through updates etc it still does not work. was refused a refund as the purchaser has since left my company leaving me with an £800 plastic box that does nothing! AVOID!!!

promptly shipped and product works really well

Excellent products... highly recommended, they do the job.. well worth the money

Great for basement where there is no signal

It doesn’t work that well but the problem is - in the UK at least- it’s the only legal solution. OFCOM are not really doing much to help the consumer hence the poor choice of products