I have a couple of sluggish feeds to a couple of radiators. Chemical
cleaners and DIY direct flushing from the mains has not helped. I wish I
could achieve something like the suck - blow effect that a sink plunger
gives to a drain blockage.

Any idea how I could do this on my microbore - perhaps by connecting
something to the top bung of the radiator with just the relevant valve
open?

On 19/12/2015 19:20, DerbyBorn wrote:
I have a couple of sluggish feeds to a couple of radiators. Chemical
cleaners and DIY direct flushing from the mains has not helped. I wish I
could achieve something like the suck - blow effect that a sink plunger
gives to a drain blockage.

Any idea how I could do this on my microbore - perhaps by connecting
something to the top bung of the radiator with just the relevant valve
open?

A while ago I discovered the thread of the hose side of a bib tap was a
standard thread.

It would then be an easy matter of lining up the fittings to blast mains
pressure water into the pipe via the valve?

On 19/12/2015 19:20, DerbyBorn wrote:
I have a couple of sluggish feeds to a couple of radiators. Chemical
cleaners and DIY direct flushing from the mains has not helped. I wish I
could achieve something like the suck - blow effect that a sink plunger
gives to a drain blockage.

Any idea how I could do this on my microbore - perhaps by connecting
something to the top bung of the radiator with just the relevant valve
open?

I've used cable (like inner cable for bike brakes) with a deliberately
frayed end to clear a blocked microbore feed to a radiator in a
neighbours house.
Slackened off the olives. One hardly leaked. Disconnected and shoved
cable down. Had estimated distance to manifold. Worked cable in pipe and
removed. Used old towels to soak up gunge until it ran clear(er)
Reconnected olive and relaxed. Worked for years!
With my similar system, when it gets first use in Autumn. I check all
the radiators, and if one seems poor, I then turn off all the others for
a while. Has worked for 30 years!

Jim

Reminds me of an anecdote from the driver of the council "soup tanker" when chemical toilets were still common. The local council had invested in a high tech lorry that had the facility to tip pails of toilet waste into a hopper that was then sucked into the tanker. When full the load would be transported to a treatment works and the sh1t blown into the works feed tanks.
The lorry had the added facility that large bore hoses could be used to attend blocked drains, couple to a blocked pipe via a manhole and suck the blockage clear.
There was a 3 storey block of flats which had occupied the drain suction team for several Saturday mornings. Finally they were sent yet again, coupled up, sucked, there was a dribble, sucked again, another dribble etc. The gang lost patience and back-blew at 30 psi. Result fountains in every bathroom on all 3 floors! The operation must have sorted the problem as the residents never complained of toilet blockages again.

Fredxxx wrote in :

On 19/12/2015 19:20, DerbyBorn wrote:
I have a couple of sluggish feeds to a couple of radiators. Chemical
cleaners and DIY direct flushing from the mains has not helped. I wish I
could achieve something like the suck - blow effect that a sink plunger
gives to a drain blockage.

Any idea how I could do this on my microbore - perhaps by connecting
something to the top bung of the radiator with just the relevant valve
open?

A while ago I discovered the thread of the hose side of a bib tap was a
standard thread.

It would then be an easy matter of lining up the fittings to blast mains
pressure water into the pipe via the valve?

Tried this.I think I need to shock the blockage.

I think (based on a radiator that I had re-piped when it was accessable)
that the blockage is at the manifold which is quite a distance away. I also
have 2 90degree bends immediately after the valve that I could remove.