Register-Plate Fires:
I have visited a significant number of distressed customers following chimney fires which started on register (closure) plates, as shown in the diagram below. Build-up of these flammable materials stems from two key sources:
(1) Falling soot & debris from the stove-pipe
(2) Twigs & nesting materials deposited by birds and vermin
This problem was brought to the attention of relevant local government authorities in a letter I sent on 15th January 2012. It was addressed to the Fire & Rescue Service, and copied to the political authority of my MP. As yet I am not aware of any corrective action – however, at the time, both these authorities took serious interest.
This matter could concern HETAS (Heating Equipment Testing & Approval Scheme) who have a focal role in authorisation systems for heating appliance installations ~ via training and granting appliance installers authority to self-certify their installation as safe.
My concern is not alone, respectable others mention it on the www. Also, knowing many installation organisations, I am certain none of them would (now or latterly) risk fitting appliances in this way…
Lastly, sweeping this type of installation can be difficult, lengthy, and with extra risks – and it is why they cost more to sweep – and normally a job for properly equipped professionals only.
Have your chimneys lined properly by professional qualified installers. Noting: lining materials must be suitable for the fuel used. Caustic emissions from some (normally coal) fuels will corrode some liners. As a general guide, use stainless 316 for wood-burning, and stainless 904 for coal-burning.
If you cannot afford to have this done, do please be vigilant: have your chimney swept regularly and often. Also, consider getting a cowl fitted to keep nesters out!
 Fuel Pile Hazards:
The ways heat is transmitted (1) Conduction, (2) Radiation, and (3) Convection. The problems shown in the diagram at (A) and (B) are self-explanatory. Radiation in these circumstances is the lesser problem, but never-the-less the risk remains. Even though in most cases, placing damp fuel close to heat sources, is to dry-it-out, which principally is a good thing.
Clearly it is important to burn dry fuel, but if it is (or becomes) tinder dry, and is close to a powerful heat source – it could catch fire – please be mindful and careful…