UK diy (uk.d-i-y) For the discussion of all topics related to diy (do-it-yourself) in the UK. All levels of experience and proficency are welcome to join in to ask questions or offer solutions.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Don Rojo
 
Posts: n/a
Default Central heating system de-sludge or just heat-exchanger de-sludge?


My home central heating system uses a combi boiler (Brittony Combi
80). I think the secondary heat exchanger is starting to get blocked
because the heat and flow rate of the domestic hot water is becoming a
little erratic. I understand the hot tapwater is heated by the central
heating water via the secondary heat exchanger. Rather than just
remove the secondary heat exchanger and addempting to desludge it, I'm
wondering if it would make more sense to desludge the whole central
heating system. I'm thinking that if I desludge the whole system,
then the secondary heat exhanger will get desludged in the process
(apart from the channels that the mains water flows through, of
course, which is probably clear anyway. Anyone agree?

I did the desludge process about three years ago, using a Fernox
desludge solution. I left the stuff in the system for a couple of days
then flushed it out and refilled with fresh water plus the standard
Fernox additive. Should it need doing again by now?

Many thanks for any advice.

Don
  #2   Report Post  
Christian McArdle
 
Posts: n/a
Default

heating system. I'm thinking that if I desludge the whole system,
then the secondary heat exhanger will get desludged in the process
(apart from the channels that the mains water flows through, of
course, which is probably clear anyway. Anyone agree?


I would have thought that it was precisely the mains water flow channels
that are the problem. The CH side should have inhibitor in it and the
calcium will have settled out long ago. The mains side has fresh calcium
rich hot water, just ripe for depositing limescale.

Christian.


  #3   Report Post  
IMM
 
Posts: n/a
Default


"Christian McArdle" wrote in message
. net...
heating system. I'm thinking that if I desludge the whole system,
then the secondary heat exhanger will get desludged in the process
(apart from the channels that the mains water flows through, of
course, which is probably clear anyway. Anyone agree?


I would have thought that it was precisely the mains water flow channels
that are the problem. The CH side should have inhibitor in it and the
calcium will have settled out long ago. The mains side has fresh calcium
rich hot water, just ripe for depositing limescale.


After 3 years the primary sealed side would need another dose of inhibitor.


  #4   Report Post  
Christian McArdle
 
Posts: n/a
Default

After 3 years the primary sealed side would need another dose of
inhibitor.

But if the system has been operating correctly, without frequent refills, 3
year old inhibitor is likely to be working well, and sludging is unlikely to
be the cause of the problems. Obviously, flushing and replacing inhibitor
every 3 years is a good thing. It's just that the DHW side of the exchanger
is more likely to have scaled up.

Christian.


  #5   Report Post  
R Taylor
 
Posts: n/a
Default

Don Rojo wrote:
My home central heating system uses a combi boiler (Brittony Combi
80). I think the secondary heat exchanger is starting to get blocked
because the heat and flow rate of the domestic hot water is becoming a
little erratic.


diverter valve ?


RT




  #7   Report Post  
Don Rojo
 
Posts: n/a
Default


Thanks to everyone for the suggestions. I think I'll try to descale
the secondary heat exchanger.

I've been getting a lot of air pockets sputtering and blasting out of
the hot taps when I turn them on. What might be the cause of that?

Thanks again,

Don
Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Draining a closed central heating system Jay and mike 1 UK diy 4 October 4th 03 05:33 AM
Central heating bypass circuit Paul Roman UK diy 14 September 15th 03 10:43 AM
Pool water in central heating system Andy Hall UK diy 1 September 2nd 03 06:01 PM


All times are GMT +1. The time now is 05:30 PM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 DIYbanter.
The comments are property of their posters.
 

About Us

"It's about DIY & home improvement"