Central Heating Issue
Discussion
Hi all, I’ve got an old school open vented boiler with cylinder in first floor and 2 tanks in the loft type system.
Shortly after the boiler fires it gets noisy and there’s a lot banging from the pipes directly above the boiler and around the pump, after 30 seconds to a minute boiler goes into standby (light turns flashing red).
Last couple of times this has happened, the boiler has been off for a day or 2 but then restarting it the system seems to work ok. It's been a couple of weeks and started playing up again yesterday.
Plumber thinks its sludge/debris in the pipes – recommends me to move to a combi system; other plumber recommended replace boiler and pump.
No-one really mentioned a flush or clean but not received full quotes yet.
The system is currently running ok, is there a quick fix? could I try an inhibitor? Or is it too late for that?
Shortly after the boiler fires it gets noisy and there’s a lot banging from the pipes directly above the boiler and around the pump, after 30 seconds to a minute boiler goes into standby (light turns flashing red).
Last couple of times this has happened, the boiler has been off for a day or 2 but then restarting it the system seems to work ok. It's been a couple of weeks and started playing up again yesterday.
Plumber thinks its sludge/debris in the pipes – recommends me to move to a combi system; other plumber recommended replace boiler and pump.
No-one really mentioned a flush or clean but not received full quotes yet.
The system is currently running ok, is there a quick fix? could I try an inhibitor? Or is it too late for that?
If sludge, and system is just working, I vote stick a filter on your return line (Screwfix magnaclean is my go to, other options available) and then run some system cleaner (Screwfix X400 is my go to, other options available) through it.
You may need to clean the filter a few times, I have seen a system where the filter completely blocked itself a good number of times.
You may need to clean the filter a few times, I have seen a system where the filter completely blocked itself a good number of times.
Could be all manner of things.
I've seen very similar symptoms due to a failing thermostat not well bonded to the heat exchanger, which let the heat ex get too hot, tripping the overheat stat.
A dirty system won't help.
A lack of flow through the boiler due to a tired or clogged pump with do the same.
Unfortunately plumbers are usually poor at diagnosing these things, it gets expensive if you let keep returning to replace random parts, to the point where a new boiler is the sensible option.
Last time I got involved with sorting an old system with similar problems, we got it running fine, for 'one more winter', then it started leaking.
I've seen very similar symptoms due to a failing thermostat not well bonded to the heat exchanger, which let the heat ex get too hot, tripping the overheat stat.
A dirty system won't help.
A lack of flow through the boiler due to a tired or clogged pump with do the same.
Unfortunately plumbers are usually poor at diagnosing these things, it gets expensive if you let keep returning to replace random parts, to the point where a new boiler is the sensible option.
Last time I got involved with sorting an old system with similar problems, we got it running fine, for 'one more winter', then it started leaking.
I helped someone elsewhere with a similar issue as initial problem - poor circulation - rads not getting hot and boiler shutting down early in a heating cycle
Circulation pump was replaced with a modern one (generated another issue which was eventually resolved)
Bonus was they sent me the old pump as I needed a new speed controller for mine (broken in a ham fisted heating engineers attemps to bleed the air by switching pump speeds quickly)
Anyway in stripping it down to remove the speed controller I decided to strip the pump head just for fun
The thing was almost totally blocked up and with a set of watchmakers screwdrivers I managed to clear only some of the channels and this was the material removed
Circulation pump was replaced with a modern one (generated another issue which was eventually resolved)
Bonus was they sent me the old pump as I needed a new speed controller for mine (broken in a ham fisted heating engineers attemps to bleed the air by switching pump speeds quickly)
Anyway in stripping it down to remove the speed controller I decided to strip the pump head just for fun
The thing was almost totally blocked up and with a set of watchmakers screwdrivers I managed to clear only some of the channels and this was the material removed
Had to do the same with my old pump a few years back
Same cleaning process got it to this
If you have no magnaclean unit (other makes avaliable) the pump and the heat exchangers make a good home for the products of corrosion in steel rads when the system is not running the right level of inhibitor chemical
Same cleaning process got it to this
If you have no magnaclean unit (other makes avaliable) the pump and the heat exchangers make a good home for the products of corrosion in steel rads when the system is not running the right level of inhibitor chemical
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