In message , MM
writes
On Fri, 6 Apr 2018 23:26:37 +0100, alan_m
wrote:

On 06/04/2018 22:41, MM wrote:


Any other suggestions most welcome!

You can probably get the hose up up the downpipe by feeding from the
bottom - the downpipe will stop the hose folding back on itself.

If you have room at the bottom of the downpipe a bare end of a hose may
be sufficient to clear a blockage but ideally a nozzle set to the
narrowest higher pressure jet will work a lot better. Feed the hose up
before turning on the water.

You don't say if the downpipe has push-fit or solvent welded fittings.
If the former you may be able to take off an angled shoe at the bottom
of the downpipe to give you more room.

If you have moss on the roof the blockage is probably that. If so just
clearing the downpipe may not be a long time cure as the moss in the
gutter will migrate to the downpipe again in heavy rainfall.

The downpipes on these fairly new houses (2004) don't end at the
bottom over a drain grille, but are fed just below the surface of the
ground and into a plastic drain connector like this:
https://www.plasticdrainage.co.uk/me...che/1/image/9d
f78eab33525d08d6e5fb8d27136e95/u/g/ug254_1.jpg

I bought a rainwater diverter:
http://www.3ptechnik.com/files/product_2000120_001.png

This requires the downpipe to be cut, thus also allowing me access to
the pipe from about 4 feet up from the ground, so I can poke suitable
tools up there.

In my experience the blockage will be the rainwater diverter itself.
Cleaning and re-fitting should clear the problem.


--
Tim Lamb