Bleeding central heating rads issue

[moogwai]

right ok...just looked at pic again,ksareen. You are right in saying that the 15mm pipe on the right is a cold feed...but this is the cold feed to the feed and expansion tank.
The cold feed i am referring to is the cold feed to the heating system which is shown on your pic 1, the one with the gate valve on coming from the bottom of the f & e tank.
This 15mm pipe tees into the 22mm pipe which is acting as the cold feed and expansion pipe for the central heating system. The blockage could well be in or around that tee....first place i'd try the magnet test on, i would then trace the 22mm pipe downwards with the magnet to see what you can find.
The gate valve in your lastest pic is the bypass for the central heating system,another place where i have found blockages in the past.
i hope this helps.

 

[ksareen]

moogwai, Yes you are right. Let me find the stubborn blockage 😡 today evening and get back..

Thanks for the info.

 

[moogwai]

good luck pal.....let us know how you get on. these things can be a pain in the buttski!

 

[Mbear]

Ksareen

The magnet will not clear any blockage at all.

It will only tell u where the blockage is, it then needs cutting out and replaced with new pipe/fittings

I got the feeling in one of ur posts on page 2 that u thought the magnet will clear the blockage. So I'm just making it clear to u mate

 

[turnpin]

surely the gate valve on the f&e tank outlet filling the heating circuit should not be there I know it will not solve your problem can anyone confirm this?

 

[moogwai]

surely the gate valve on the f&e tank outlet filling the heating circuit should not be there I know it will not solve your problem can anyone confirm this?

yep, i agree..there's not meant to be any obstuction on f & e pipework which could cause a blockage...i remember that from my college days.

 

[ksareen]

Dear all

Devoted couple of hours yestreday to save being reprimanded today😀

Results:
1. DHW running fine now, unscrewed pump screw and hot water cylinder union at top to bleed air.
2. All rads bled, CH working fine now as it should. Monster of a job really of reverse filling with mains water. The drain plug screw even when open a little leaks like hell, especially when mains is turned on full force.
3. I think I've found blockage, pic attached with area highlighted. I tried various settings on the motorised valve and with both the drain plugs but I am sure mains pressure was not reaching the area of blockage. Although I find a little magnetic effect at some TEEs, magnet hangs on to the pipe at this Tee.
4. The system is running now as before with all rads incl new ones getting warm, BUT there is a blockage (not good as moogwai advised). FE tank water is like new (just replaced) and is not mixing with the CH one, so no point adding the cleaner or inhibitor.

If you could please look at the attached pic and advise how to clear this blockage? Could I undo the pump and poke the pipe as its quite close to the pump? What are the 2 valves on either side of pump? What are they for and how do you operate them?

Regarding the gate valve on the cold outlet feed pipe on FE tank, I am not as educated as you on these things but I found that very useful to empty the FE tank and isolate the CH from FE tank. In fact I've another idea now, should I try to mains flush the CH by opening the drain plug and connecting the CH feed at gate valve (undoing the gate valve) to mains pressure. Would that help to unblock the blockage?

Thanks once again.

 

[Mbear]

Dear all

Devoted couple of hours yestreday to save being reprimanded today😀

Results:
1. DHW running fine now, unscrewed pump screw and hot water cylinder union at top to bleed air.
2. All rads bled, CH working fine now as it should. Monster of a job really of reverse filling with mains water. The drain plug screw even when open a little leaks like hell, especially when mains is turned on full force.
3. I think I've found blockage, pic attached with area highlighted. I tried various settings on the motorised valve and with both the drain plugs but I am sure mains pressure was not reaching the area of blockage. Although I find a little magnetic effect at some TEEs, magnet hangs on to the pipe at this Tee.

this tee looks like you cold feed

4. The system is running now as before with all rads incl new ones getting warm, BUT there is a blockage (not good as moogwai advised). FE tank water is like new (just replaced) and is not mixing with the CH one, so no point adding the cleaner or inhibitor.

If you could please look at the attached pic and advise how to clear this blockage? Could I undo the pump and poke the pipe as its quite close to the pump?

it needs to be cut out and repiped

What are the 2 valves on either side of pump? What are they for and how do you operate them?

theyre called pump valves, u screw the spindle clockwise to close the valve (beware, pump valves that havnt been used in yrs can start leaking when closed/opened,even more likely as youve defo got sludge in the system)

Regarding the gate valve on the cold outlet feed pipe on FE tank, I am not as educated as you on these things but I found that very useful to empty the FE tank and isolate the CH from FE tank. In fact I've another idea now, should I try to mains flush the CH by opening the drain plug and connecting the CH feed at gate valve (undoing the gate valve) to mains pressure. Would that help to unblock the blockage?

most likely not, you'll most likely do some more damage elsewhere

it needs cutting out bud, i know its not what u want to hear but thats what needs done and trust me once its cut out the system will fill no problem.

Thanks once again.

ksareen, i know u dont want to cut it out but the issue is only gona get worse, the chokage will get bigger. do it now while the weather is still good

best of luck mbear

 

[moogwai]

ksareen, i know u dont want to cut it out but the issue is only gona get worse, the chokage will get bigger. do it now while the weather is still good

best of luck mbear

agreed.

 

[ksareen]

Thanks for your input. Its a job for the weekend then..

Do I need to drain the system again?

What fittings would be easiest to replace this Tee and elbow with.

I am a fan of solder-ring, do you get them in 22mm as well?

OR should I put compression ones in case these pipes are likely to block again in future?

P.S. What I don't understand is that this pipe seems to input to the pump. If this is choked, how is the pump running?

 

[Mbear]

Thanks for your input. Its a job for the weekend then..

Do I need to drain the system again?

yes mate, drain the entire system

What fittings would be easiest to replace this Tee and elbow with.

I am a fan of solder-ring, do you get them in 22mm as well?

yes u can

OR should I put compression ones in case these pipes are likely to block again in future?

using compression makes it easier to unblock should it re-occurr. i always fit compression on this type of job

P.S. What I don't understand is that this pipe seems to input to the pump. If this is choked, how is the pump running?

the pump will still run, as its electrical, leaving the blockage in place will eventually burnt out the pump, which will cost about £80 for a new grundfos

 

[ksareen]

Mbear

You might have a point, the pump does get quite hot when running and I was not too sure if it was supposed to be like this. Maybe its not getting enough water through that pipe.

However, interesting thing is that rads still get hot everywhere which means that the pump is still circulating the water??

 

[Gray0689]

Get a plumber stop trying to be cheap you will balls it up you have not got a clue

 

[ksareen]

Mbear, Moogwai and other helpful chaps,

Thaks for your help. The elbow had around 99% blockage (forgot to take pics). Cut it through the middle with an angle grinder. Warmed up and removed the solder joints. Cleaned all the pipes around boiler/ pump thoroughly after taking them apart and put compression fittings instead.

Rads filled up with no issues (and very fast). Started the system, all working fine, no leaks, excellent hot water and all rads are warming up. The pump does not get half as hot as before which is good.

Without your help, I am sure it would have not been this easy. Many thanks once again.

The only issue is adding cleaner and inhibitor. I've Kilrock cleaner from B&Q but I am thinking of leaving it till winters as even if I add it now, it won't circulate as heating is OFF.

Gray0689: Makes me wonder why people like you join forums when this is the best advice you can offer.

 

[Gray0689]

Your descrpion makes me think your a muppet I'm a pro if I don't know how to do somthing and it's not my profesion I will pay to get if fixed not be tight

 

[ksareen]

Have you heard in your life about "learning" or is that too much to expect from a "pro" 😛

If your plumbing abilities are as good as your judging, I should really be praying for your customers. My final advice for you is to see a doctor.

 

[Gray0689]

Lol I defo don't need you advice

 

[Toddyplumb]

Dont forget to check for pump over

 

[moogwai]

gray0689 you made me laff with yer comments.....ksareen glad you finally got it sorted.

 

[Gray0689]

I hate peaple who take the micky he knows nothing just to tight to get a good plumber