Occasional drop outs of signal - combiner?

Supercell

My mother recently had an aerial installed professionally and they used a combiner to use the existing satellite cables she had in place.

For the most part reception is perfect, signal seems to be good and strong. The terrestrial stb has a signal meter on it and it shows the signal strenght to be almost 100% anytime i've been there .
However she is complaining that occasionally she isn't getting any terrestrial signal at all but satellite always works. This is in both rooms on two different tuners (one is built into her Samsung TV and the other is a stb i forget the name of)

She has an old SkyHD box in one room and a Humax HDR-1000S in the other room connected to a standard Sky dish with quad lnb.
The terrestrial aerial is connected using a combiner to the coaxial cable and separated at the stb end. I havent seen what combiner is used outside (it's up on the roof), but here is a picture of the one at the tv end :-



Could it be water ingress into the external combiner or something else? I'm pretty stumped, it doesn't seem to be weather related and the aerial was installed pretty high up with good line of sight to Three Rock (she lives in Dalkey) so I dont think its that.

I was thinking of replacing the combiner/s outside first as they are relatively inexpensive. Any one any other recommendations?
Is it worthwhile getting one combiner over another , are the better ones than others?

Peter Rhea

The outside combiner should be a 4-way version of the indoor one, with weatherproof enclosure. It will have 5 inputs (4 satellite, 1 terrestrial) & 4 outputs with combined signal.

This means the terrestrial signal is being split 4 ways & mightn't necessarily be strong enough without amplification. The installer should be able to measure levels properly & make sure there is an extra margin too.

PogMoThoin

You need to get him back with his terrestrial signal meter, sounds like there isn't enough coming in to allow for the drop, may need amplifying.