Megaflow system radiators not working

[bleedingdavid]

My daughters Megaflow system has been working OK for some time. Recently some of the downstairs radiators remain cold while fully on ... others are very hot. All upstairs appear OK. Bleeding the offending rads produces water but no improvement.

With boiler on and thermostat calling for heat ,,, Thought I would try turning off all working rads. Noting all un-working. Then turning off the non working ones one at a time back to leave only one on .... when and if that got hot ... turn on next non worker etc etc

Is this a good idea ??? Is there a better one???

 

[secret squirrel]

do you have a red cylinder near the mega flow?

if yes check the pressure. Should be 1.5 bar when cold

if it is 1.5 bar and everything else is working could be the pump

if no, go into the loft and check the small tank in the loft is there water init, if there is and no air in the system could be the pump

 

[Simon F]

My daughters Megaflow system has been working OK for some time. Recently some of the downstairs radiators remain cold while fully on ... others are very hot. All upstairs appear OK. Bleeding the offending rads produces water but no improvement.

With boiler on and thermostat calling for heat ,,, Thought I would try turning off all working rads. Noting all un-working. Then turning off the non working ones one at a time back to leave only one on .... when and if that got hot ... turn on next non worker etc etc

Is this a good idea ??? Is there a better one???

its a good idea as a way to test for an air lock/blockage. be cautious about turning all working rads of, might strain the pump if there is no circulation

 

[bleedingdavid]

SS thanks for the help ... the pressure was boosted back to normal a few weeks back when it was noticed to be low ...

... the pump is hot and working (motor running) ... can pumps be running and not pump efficiently (e.g. with age etc)???(10 years old). They say no header tank in loft (closed vented system???).

Plan A has now got all but 2 rads working normally and even those two showing some heat .... so progress !!

Pump not producing enough va va voom does seem consistent with symptoms ... also partial blockage .... either unbalancing system.

We plan to "force" the two remaining offenders with Plan A to clear any potential blockages ... the open all up and rebalance

... that should focus it on pump efficiency if we still get issues ...???

Very much appreciate your time and knowledge

 

[bleedingdavid]

many thanks ... yes! ... even with my inadequate knowledge, instinct said to keep open a least one rad ... but of course with a potential block you can never tell full situation. Plan A has made significant progress .... but pump pressure/flow(?) is very consistent with symptoms.

We plan to force the 2 still a bit slow and rebalance .. and review.

Help much appreciated

 

[dontknowitall]

As soon as someone says hot upstairs rads and cold downstairs I go straight to the pump (heat rises but needs to be pumped to send water to the downstairs pipework.

The pump might be hot and might be vibrating but that doesn't necessarily mean it's working. When the heating's turned on the pipe going to the pump will be warm and getting hotter. The pipe after the pump should be heating up at exactly the same rate. If not, the pump is definitely at fault.

Turn off heating. If you remove the bleed (the large screw and have a towel handy), water should come out. If not, there's a blockage or air in the system at this point. If it does then turn motor with a 3mm screwdriver. If this does not move freely then the pump is shot.

 

[bleedingdavid]

thanks ... we seem to be getting some pumping but your advice re pump well received. It has jogged my memory about a pump problem many years ago .... had got jammed with a chunk of limescale or similar ... few twists with large screwdriver got it free again and working till we had time to do a proper clean. Will take a look at this one. cheers

 

[bleedingdavid]

PS ... how do I put a sludge remover into a closed system?? (no header in loft) ?????

 

[stevetheplumber]

iff the pump is very hot change it

 

[Simon F]

PS ... how do I put a sludge remover into a closed system?? (no header in loft) ?????

close off one radiator, one that has more volume than the additive. empty the radiator and put the sludge remover into one of the top tappings. a towel radiator is easy if you dont have a kit to put the solution in with, because the tapping is on the top, easy to fill with a funnel.

 

[gaspastemania]

i would get a plumber in to be honest as you could end up doing more harm than good with limited knowledge .

 

[dontknowitall]

PS ... how do I put a sludge remover into a closed system?? (no header in loft) ?????

You need to take an end piece of the top of an upstairs radiator (or the towel rail if there is one as this is much easier.) Or if the valves are working properly and there's a drain valve of a downstairs radiator you can do it this way.

First drain down enough so you can get at least a litre of liquid back into the system. With the downstairs radiator, drain around 3 Tesco ice cream cartons off.

Rig up a 15mm compression piece or isolation valve and have a 15mm piece of bent copper pipe. Put small hole in inhibitor bottle where it will pour then put another hole in opposite to let air in. Then pour slowly. Top up system with water, bleed and you're done. I did one yesterday and it took 5 minutes.

 

[dontknowitall]

Or get a plumber in - much less messy that way!

 

[bleedingdavid]

good stuff thanks

 

[bleedingdavid]

I understand your point ... but from my experience ... it is a good idea to understand a little about what the problem is or is not BEFORE you do that ... also a large number of problems have very simple answers ... requiring a minimum of skill ... I have a great regard for the skills and knowledge of tradespeople (like bankers, not all are honest!) ... but after all it is skill and knowledge that can be learned by normal people with average IQ etc etc ... so why not me ... for this or next time??? But you are right ...the concept of this forum should only apply to safe things that almost anyone can do to assist in solving or diagnosing the problem ... and nothing dangerous or major.

 

[bleedingdavid]

thanks ... that is the whole point of the forum for me ... What can I do? What not? ... would be good to know what damage one can do for example?