i was practicing a bit earlier with a heater switched on near to me, it’s the type that blows hot air through vents - after a few minutes the reed went out of tune and sounded muffled - i’m hopeful it will go back to normal - anyone else noticed this phenomenon?
The heater dries out the reed. Perfectly normal. Humidify.
would storage heaters be better?
today i tried my chanter and the back d was cracking and second octave e was scratchy - i think this might precede the heater problem but perhaps have been made worse by it (i have been doing some busking in coldish weather too) - my approach to reed maintenance is never to do anything except adjust the bridle because i don’t have the skills to do anything else- is there any chance it will come back into its own?
If your problems are due to low humidity, then my experience is yes, it will come back to normal after you humidify the space the pipes are and that you play in.
Forced air heating is the worst for de-humidfying. A radiator type or almost anything else is better than forced air heat.
Yes, leave it alone and it should recover as its environment improves.
Taking a reed out into cold weather dries it and will probably cause various issues, especially with the back d and the second octave. Bringing it back indoors where it is exposed to blowing warm air will further dry out the reed, sometimes leading to complete shutdown. My experience has been that reeds will recover once the temperature and—more importantly—humidity return to a tolerable level. Warm but non-blowing air will dry the reed, but probably at a slower rate than blown warm air. If you’re not already, you might consider storing your instrument in a closed case with a source of moisture, an apple or something like the Oasis case humidifier. It will still wonk out when you play it in a dry environment, but at least it will have a chance to recover between exposures.
I don’t know what you mean by a “storage heater,” but if you mean the kind that has an oil filled radiator, yes, it will be better than blowing hot air, but will still dry out the reed. A pot of water sitting on the radiator will add some humidity to the room and can help.
That would do it 
. Had a little “concert” streaming my music online, and the heat from my computer raised the temp in the room a bit and completely changed the tuning of my reed in about 15 minutes. Reeds like consistent temps and humidity.
Another thing - if you haven’t already, buy an hygrometer; like all modern electronic devices they are dirt cheap nowadays. Keep it in your pipe case, and note the humidity when you begin to have problems. My (made in Ireland and France) reeds do OK down to about 30-40% humidity, after that I must humidify the room for them to play well.
Errr… As opposed to…? A radiator? 
Yes, my reed has the same problem with low humidity, the sound muffles, also the Bottom D gurgles like crazy and is generally unstable(I have good days and bad days in the winter with it though.), and the low E plays so sharp that it needs tape. During the summer and autumn is when mine plays best.
Try looking for These if you want.
I still play it like a masochist, but if I’m TOO frustrated, I just put it away…
This is a big problem in the Upper Midwest (US), where winters are cold, dry, and long. Most of my piper friends use some combination of entire-room/house humidifiers, case humidifiers, and in the case of Tommykleen, bellows humidifiers.
None of that has ever worked very well for me. Instead, I swap out my “normal” reed with a wide-open, dry-weather chanter reed, from December through April or so.
Just on my concert set, though; for some reason my flat chanters work more or less OK even in January.
Good luck,
Mick
Same here. I just popped in a reed that sounded AWFUL – sharpish, honky, blaring, and generally obnoxious – during our very humid summer, and it is an entirely different critter now. I eased the bridle pressure just a little bit over the course of several days, but basically, what I’d written off as a dud reed is glorious this winter. A joy to play, responsive and vibrant, and oodles of tone-color options. … It’s aliiiiive!
I also humidify the room and have a case humidifier, but those add up to about 45 - 50% on a good day.
Reeds, and their makers, never cease to amaze me.