no circulation help

[malkie]

Hello im just wondering if you can help im a bit stuck ive been out to a power flush and i had warned that it may not work so i went done the flush and still the same proplem which is "the system is a conventianl boiler, back boiler the customer rang me on sunday he fitted a new pump but the rads still didnt work,the hot water is off gravity so when i went i checked the water level in header tank all ok,i bled the rads all filled up ok then i turned downstairs off andput heat on the rads got hot but as soon as turned downstairs on only the kitchen rad got hot,i found that its pumping over when pump on 2 or 3 it just doesnt sem to be circulating now when i looked at the pipework at the back boiler on the flow is a old fitting which is about 3" long 22mm and has a vent in the middle which a vent key fits but do you think it could be some sort of dumblift valve. When the system nees venting the tank is reblenshing ok and i tried banking the expansion and cold feed just to see if it circulated when it couldnt push over but no joy,any ideas boys i spent all day flushing it and did get a hell of a lot of sludge out and the customers told me it is better but i cant get it to heat up when all rads are on,all rads will heat up if others turned off and ive balanced it right down

 

[ChrisR]

I'd try a new pump, and while the old one's out, thrust things up pipes to check they're clear of the hard stuff. WIckes do a good drain spring or two for that! Unless you use dangerous chems, nothing much shifts the hard scale.
If the pump's perfect you can always put it back if they moan.

 

[twgas]

on the flow is a old fitting which is about 3" long 22mm and has a vent in the middle which a vent key fits but do you think it could be some sort of dumblift valve

sounds as though this is stuck/sludged up - new anti gravity valve reqd.

 

[malkie]

Cheers boys i went today armed with a new pump,anti gravity valve and i bought some drain springs from wickes so i got there at 10am and i didnt mess about i draines it down had to cut the pipework above the anti grav valve as it was impossible to undo it hadnt moved for 30 years so i used pushfit and yes it was metric so i had to get the old pipe spotless and use a 22x3/4 coupling and without looking solder it it was yorkshire so i was ok then i connected back up and id pushed the springs up and down and when i turned on it was better my miles but not 100% so i fitted a new pump even though the customer had fitted one last weekend,he told me "if this one you fit works then take it out and im going to get my new replaced and fit a new myself" so it did the job and i had to take it out and i got paid and left. I got a call at 7.30 from his wife "hello i cant talk loud he will hear me hes fitted 2 new pumps and WHAT THE BLOODY HELL WAS THAT,hes floodimg the place please help" so i live 2 minutes away i got there to find him in the garden sitting in the middle holding his chest and her shouting how much of a stupid b............ he is,hed got p.... off and gone to cut the pipe above the new anti grav valve that id fitted but he hadnt seen the cable running by it and he cut into the pipe 1/2 way but then into the cable and he hadnt turned the header tank off hed openend the drain off so next thing he was getting drenched then bang flew across the room and the water was just gushing out when i got there so i turned the power off then the main water and wrapped denso around the pipe and when it drained i seen hed fitted the pump the wrong way and i fixed it and he said "how much do i owe you" i said listen take her out for a meal or put it towards the divorce settlement" anyway the two have just knocked with a card with £100 in and flowers for the missus so i gave her the ton as well so it worked out well im just waiting for her to get out the bath i just hope im drunk enough to face seeing her naked erm im off to get another 2 litres of vodka