No Hot Water after Rad Swap out

[storm7]

Help please...

I have a gravity fed hot water/central heating system and decided to do some diy and swap out a rad in one of the bedrooms.

I emptied the system/s and connected the rad and bled them then did the obligatory bleeding and the central heating works fine.

However, now I can't get any hot water. I switched the control to hot water only and the bolier (an ancient Potterton) fires up for about 3 mins then switches off.

Suspecting an air lock (reading the text on here) I connected the cold to the hot circuit and until it was coming out of the cold tank overflow. I also bled the air valve on the hot water cylinder-just a trickle or air came out-but still no joy.

Any ideas would be most appreciated before I resort to a call to my friendly plumber!!!

Thanks

 

[gas4you]

Is the primary flow getting hot at all off the boiler?

Sounds like a blockage in the primary return wher it comes off the hw cylinder.

 

[namsag]

Which old potterton

 

[storm7]

Thanks for the swift response Dave

The primary flow from the bolier is indeed getting hot however no feed into the hot cylinder is getting in the slightest 'warm'

 

[storm7]

It is a flamingo 50s

Cheers

 

[gas4you]

I'd still suspect a blockage as previously said.

 

[storm7]

Is curing the blockage from the primary return off the cyclinder a job for a plumber? or are there any diy tips for this?

Thanks

 

[namsag]

Take outer case off just put hot water on and remove the thermostat phial on boiler from its pocket and let system boil up for a bit this will remove any air lock..
It will sound like someone is hitting it with a hammer dont let it bang for more than say 20 seconds you may have to do this a few times to shift it.. and remember an replace thermostat in pocket when done

 

[storm7]

Any ideas on where I could find the thermostat phial on the boiler?

Cheers

 

[namsag]

With case off you will see it right in front of you

 

[storm7]

Got it - wasn't expecting it to be so obvious...

Did what you said and after a bit of upstairs/downstairs, banging and over flow of piping hot water from the header tank the hw cylinder is now getting warm and we have hot water coming from the taps.

Many thanks for the advice - the kids can have a bath tonight!

Thanks,

 

[namsag]

G4Y .. Gravity always start with the basics especially after a drain down.. Don`t like to tell people how to boil a system but depending on boiler and gut feeling you can only advice after all it is a diy site

 

[gas4you]

I agree namsag, but I am very reluctant to offer the advice you did to a diyer, thats all.

At least it worked though and he got away with it