On 22/01/2018 21:14, John Rumm wrote:
On 22/01/2018 20:54, Tim+ wrote:
John Rumm wrote:
On 22/01/2018 18:35, Tim+ wrote:
BG came around to my Mums to look at her combi which wouldnt
supply hot
water when the CH wasnt calling for heat.
Apparently some crud in the valve which they sorted and to their
credit,
they *didnt* try and sell her a new boiler. Instead they are pushing a
system power flush for £600 which sounds a lot to me.
Assuming Im prepared to spend a day messing around looking for
drain cocks
and bits of hosepipe, is there any reason I cant do this myself?
No, its quite doable. You can even hire the power flush kit if you fancy
doing it that way.
Mains water flush works quite well IME. I did not bother taking each rad
out of circuit, but did arrange it so that each rad got full mains flow
all to itself for several mins by closing off flow to all rads bar the
one being flushed.* would start it going wait til it ran clear, and then
give it a couple more mins (some suggest bumping it with a rubber hammer
as well to dislodge more crud). Then move through them one by one - open
flow through the next, close off the previous etc (i.e. making sure not
to cut off a water path altogether). When All are done, reverse the flow
direction and do it again:
http://wiki.diyfaq.org.uk/index.php?...ating_flushing
Cheers.
Is there a recommended flushing substance to treat the system with
prior to
a full flush?
Sentinel et al do system cleaners that you can lob in upto a couple of
weeks prior to flushing.
Is there any danger of them loosening crud that might then cause boiler
problems again?
You are better off taking the boiler out of circuit[1] so that you don't
flush any crud through it. Especially if its a modern boiler (the high
efficiency HX have lots of small water pathways and heatsink fins that
intrude into the flow - they are easy to block or erode with particulate
contaminated flow).
[1] either temporary re-pipig, or just turning off the flow and return
service valve.
I reckon a Magnaclean is not a bad investment. Apart from collecting
magnetite, they provide a quick and easy way to add inhibitor.