Horizontal lines on bbc channels

s4uch1e

My 82 year old father has called me for help on his bbc channels,  he looking forward to watching the snooker this week but unfortunately all his bbc channels are full of horizontal lines making it unwatchable  while all other channels are perfect. 
Any advice or tips on whats causing this or how too repair it. He lives by himself and really needs his tv working especially in these times

JJ_Egan

One aerial connections .

Two Retune channels on TV

Three aerial at fault moves etc .

Does he not have BB for IPlayer catchup .

s4uch1e

Unfortunately no bb, tried ti get him to accept sky but refuses.
Just strange its only the bbc channels that are affected 

jon81uk

s4uch1e said:

Unfortunately no bb, tried ti get him to accept sky but refuses.
Just strange its only the bbc channels that are affected 

With digital TV channels are grouped, so most BBC channels are all on one multiplex, so if there is an problem picking up that frequency it would affect all those channels.
If the connections to the aerial look OK they should retune and then if that doesn't solve it then check the aerial is OK, might need an installer to look into it.

Rodders53

What TV is it?  Is it SD only or a Freeview HD-capable TV?  If HD capable try tuning to 102 rather than 2 for BBC TWO?  A different multiplex, different frequency may work OK short-term?
Also check if there are better versions of the BBC channels stored in the 800s of the TV?

Normal best advice is to NOT retune when there are reception issues, as that can lose the tuning place-holders and make fault finding / clearing the fault more difficult.

Is it his own home with his own aerial (rooftop, loft mounted or    room aerial)? 
Or is it a shared/communal aerial system? (If so ask others on it whether they are suffering the same problem, and report it to the Managing Agents).

I'd suspect the most likely is a dodgy aerial connection (i.e. one that has come loose).  This may need any hand-made TV plugs checked and remade. https://www.aerialsandtv.com/knowledge/how-to-attach-wire-up-plugs-aerials-and-wall-plates
Check the plug(s) are fitted properly and haven't come loose.  A push in and twist may fix a poor connection to TV or wall plate outlet.
Similarly, a wall plate outlet may need attention / re-making. 
Moulded fly leads?  Try alternatives.
HDMI connected kit (recorders, DVD players)?  Keep hdmi and TV cables well apart.  The two can cross interfere and it's often only one multiplex that is affected.  (Again try an alternative hdmi if possible, some are better than others).

It may, though, also be interference: 
Central heating, or electric heater, or water heater thermostat switches can spark and 'radiate RF noise' when faulty; that can give picture breakup not too dissimilar to the lines described.  That will need likely fixing by someone 'who can', though.  It may only affect the weakest received channels;  although often all channels are similarly affected.

Can he take a picture of these lines on a BBC channel and another of other TV channels that are OK and send them to you to share here?
Can you guide him to find the signal level and quality metering on the TV and report the numbers for the BBC problem and other channels? 
That may give a further clue as to the problem.