Noisy Central Heating

[zidane]

Hi Guys, slight problem with my central heating, the rads seem to make a humming noise and also most of the time the rads are hot but I seem to get cold spots on two rads (living room & 1 bedroom) the other 5 are piping hot all the time. I fitted new rads upstairs (the downstairs ones are old not sure of age prob 10yrs) the copper pipe is 8mm microbore & I have two tanks in the loft and a hot water tank on my second floor.

Also when I drain it off lots of black stuff comes out ( probably sludge not sure) I'm thinking about using Sentinel cleaner could anyone advise which one I should use (there are so many) and how to use it, & if it would do any good I heard of power flush but dont really want to do that.

Second prob if anyone can advise my boiler is a glow worm hideaway with a flue Ive just moved into my property but cant turn the temp down on the water for the taps, there is a temp knob on the boiler but this seems to control the central heating, Ive noticed a knob on the hot water tank with number 1 - 6 does this control the water temp? Any help would be great!! sorry for the essay but Id thought I would give u as much info as possible!!

 

[zidane]

sorry I was meant to post a new topic but I was reading the current one which related to mine & I accidentaly posted my newtopic on some one elses!! SORRY!!!

 

[zidane]

some body please advise Ive been waiting ages!! Im really sorry I wont double post again!! whatever happened to guilty with extenuating circumstances

 

[JohnD]

cold spots at the bottom or middle of a rad are probably partial sludge blockage

Sentinel X400 will probably loosen it. You can circulate it for a couple of weeks before draining and flushing. You can also look up mains-water flush in the FAQs I think (or our Wiki). You could also fit a Magnaclean which will trap remaining sludge particles that come loose even after you have flushed and refilled with inhibitor. You will never clean it all out. This stops it accumulating into new blockages. You can also take off sludgy rads and squirt them through with a hosepipe in the garden. The black sludge will stain any carpets or wallpaper it touches.

When you refill you must include inhibitor or it will corrode again.

Also bale out the sludge from your F&E tank first so it does not flow down into the rads. Scrub and sponge it clean with the ball valve tied up. Fit a close fitting lid and an insulating jacket.

post photographs of whatever controls you have on or around your boiler and cylinder as I don't understand what you mean.

 

[zidane]

thanks mate will try that, have you got any ideas how I can turn the temp on the water in my taps at the moment its boiling hot. There is a blue knob on the hot water cylinder with a screw in it currently its on 6, dos this adjust the temp if so how do I turn it? will take photos in morning camera in wifes room cant really go in there unless I want to die

 

[JohnD]

possibly if it look like this and is strapped to the side of the cylinder

http://www.screwfix.com/prods/40051...Thermostat;jsessionid=1OAJXN4BT00LSCSTHZOCFGA

 

[zidane]

no havent got nothing like that at all just a blue knob on the hot water pipe going directly into the cylinder itself, would this be put else where in the house?

 

[JohnD]

does it look like a Cyltrol Valve?

turn the knob carefully, the spindle might be stuck and the knob will be damaged if you force it. A new one is very expensive

http://www.climate-eu.invensys.com/...-4CF0-A6D1-FA26D34B0370/7831/D337_Cyltrol.pdf

They are not often used these days

 

[zidane]

thats the one!! your a genius!! but I cant seem to turn it, do I need to push it in and turn or do get a flat headed screw driver and turn the screw in it to turn it. It has two groves on the end of it & its on six at the moment what setting should it be on?

I must thank you for your help, you have actually gone beyond the call of duty!!

 

[JohnD]

It might be stuck, or the knob might have been fixed in place against its stops.

Observe that the blue knob has two stops on it which locate in the brass to prevent it moving too far. the knob might have been fitted so that it is fixed and cannot be tampered with. Each number on the knob makes about 5 degrees C difference. You need to rotate it slightly to a lower number. You can remove the screw to take the knob off and you may be able to turn the spindle a bit with pliers. Do not damage the splines. Do not turn it far or you will take it away from the adjusted point. Maybe move it a fraction each day until it seems right. It is not supposed to rotate more than about 300 degrees rotation from the point set in the factory.

p.s. if you turn it too far from its balance point, it will be either permanently on, or permanetly off. you need it to be at the balance point so that it just opens or shuts at the right temperature.

 

[zidane]

yes you are right it is currently located between the two brass bits, I will take off the screw and turn it, but before I do it can I just ask is there no way to turn it with taking off the screw? for example push in or out then turn?

 

[JohnD]

no

 

[zidane]

I have turned it slightly & it has started to leak & wont stop!! any advice? I wish I never touched it, me & my good ideas!!

 

[JohnD]

phone
Craig May
Customer Care Centre
Invensys Controls UK Ltd
Tel No: 0845 130 5522

ask the price of the repair kit mentioned in the instructions for this part.

I think a new valve is in the region of £80

I don't think you can change it without draining the system.

you could probably fit a plain elbow (no valve) at lower cost but the cylinder will then get very hot.

if there is a brass nut visible on a gland round the spindle you might be able to turn it just a fraction to tighten it