No CH after rads replaced...

[CP]

Hi to all, and hope your Christmas was warmer than mine...

Have a problem, and hope you might be able to throw some light on things...have an Ideal Elan RS60 boiler in my flat, providing hw and ch to 6 rads in a 2-bed flat. No idea how old it is, but I've been here 5 years with no problems at all. Had to replace 3 of the old rads due to age/condition, had previously replaced the other 3 with no problems. Did all the draining down & replacement, refilling, bleeding, etc. as I did previously, but this time I'm getting no heating in any of the rads...hot water feeding back into header tank in the loft and ketting boiler. Have used Fernox/descaler/protector and the like afterwards, but no joy - boiler was banging like crazy until Fernox added, now quiet, but still no heat. Have bled the pump (Grundfos 15/50), and just water coming out, and pump working fine. Have drained down and refilled again since, but still no heat. Did have hot water feeding into the rads for about an hour after first replacement/bleeding/refilling, now nothing...any thoughts? Please...??

 

[Bahco]

Did you manually open your mid pos valve to allow water into heating side.

 

[CP]

Yes...did everything exactly as I did when I replaced the first three rads...

 

[kevplumb]

sure all the rad valves are open

air vents all bled etc

 

[brumylad]

? blocked cold feed ?

check using a magnet.

 

[kevplumb]

scuuuuse me blocked cold feed
how did the poster manage to fill and drain the system twice then

 

[CP]

sure all the rad valves are open

air vents all bled etc

Yes to both...

...I have been told by "various" that:

a) there is an airlock in the return feed (if so, how do I get rid?)

b) there is a blockage in the return feed pipe (if that's the case, why didn't the Fernox remove it and where would something that large come from/not shown itself before? Also, how come I was able to get heat in the rads, albeit for a short time?)

c) the 3-way port has "gone" (if so, how come I still get hot water in the bathroom, kitchen, etc.?)

Answers on a postcard please...

 

[kevplumb]

could try slackening the return on the cylinder

if the three port valve has gone it will fill the rads through the return
try locking the lever open

 

[CP]

sure all the rad valves are open

air vents all bled etc

Yes to both...

...I have been told by "various" that:

a) there is an airlock in the return feed (if so, how do I get rid?)

b) there is a blockage in the return feed pipe (if that's the case, why didn't the Fernox remove it and where would something that large come from/not shown itself before? Also, how come I was able to get heat in the rads, albeit for a short time?)

c) the 3-way port has "gone" (if so, how come I still get hot water in the bathroom, kitchen, etc.?)

Answers on a postcard please...

Hi guys...

...further to this, I've been away with work last couple of months, so not been able to pick up on this problem I've had - anyway, just got back this week, so thought I'd post an update - any help/info would be great...

...have refilled the system, and done the usual bleeding of rads, etc. Checked the pump and 3-way, and all is fine with those. Fired up the boiler, and got hot water to ALL the rads, but only for a short while...the boiler is still kettling and sending hot water back to the expansion tank. I noticed that the knocking noise is emanating from the return pipe from the boiler only, and water is filling the boiler after the kettling sequence. Am I right in thinking that airlock (if that's what it is) is in the return pipe, and if so, how do I force the air out? Can't understand how it would be a blockage as this problem didn't occur when I originally replaced rads...

 

[brumylad]

try back filling the system by removing one rad. conecting one end of a washing machin hose to the rad valve and the other end to a mains w/m tap (double check valve protected of course). This will fill the header tank of course, so careful you don't bring the ceiling down by over doing it. Check the system has a vent pipe before you do this, you don't want to subject the boiler heat exchanger to mains pressure.

 

[kevplumb]

"c) the 3-way port has "gone" (if so, how come I still get hot water in the bathroom, kitchen, etc.?"

cos hot water is the default position

 

[CP]

Almost forgot to say, all rads are on the same level (1st floor of conversion flat), with expansion tank, pump and 3-way port upstairs in the loft...don't know if that makes any difference? Also, the water drained from the system is almost clear, which I guess rules out the sludge issue??