8mm microbore rad not getting hot

[Doc Hudson]

You may benefit from more experienced plumbers rather than sparks! 

Im no plumber so can't really say, but would you ask your dentist, for advice about your eyes?       

Bit of an irrelevant example?

The real world of business has moved on a long way from single skill or trade per worker. It is not uncommon for tradespersons to be multi skilled in the modern workplace. For example; An electric shower, A central heating pump, A motorised valve, An immersion heater etc. all require electrical and plumbing skills to install or replace and often to fully diagnose faults. To think you need two people in attendance to work on these products, (an electrician and a plumber) is a bit naïve. They can be done by a suitably competent single person. As such some members may have more skills that just their electrical knowledge and the forum will not prohibit those with that knowledge from sharing it.

Obviously we have no objections to Luke asking questions anywhere he chooses on the internet. But your comments would suggest that the combined knowledge of all members of the forum does not exceed your plumbing knowledge. If you do not feel confident to offer constructive assistance to the question, it is probably best to just read but not post. (as per your own comment "I'm no plumber so can't really say"). If every member who couldn't answer a question added a post to say "I don't know so can't say" it would just clutter the forum in a similar manner to spam posts. Please in the future take note of your own advice and only reply to items you have some constructive input to, Thank You.

Doc H.

 

[Murdoch]

Doc H .... Here you go again.

all I did was suggest he should also seek advice from a plumbers forum ...... What's wrong with that?

 

[Andy™]

nothing. it was the bit after that

 

[Sharpend]

Ideally what you need to do is lift a few floorboards to locate the manifold. This way you can check where the blockage lies, it will also be easier to resolve if you disconnect the pipe from the manifold and work on it alone. 

 

[Doc Hudson]

Doc H .... Here you go again.

all I did was suggest he should also seek advice from a plumbers forum ...... What's wrong with that?

If you actually read the whole of the thread it would appear as though Luke is getting some constructive advice from some of our members, that is being worked through in a systematic way. If you also read my post Electrical and Plumbing skills can and do co-exist within a single trades person. As such questions that do not direct relate to pure electrical problems can be answered and have been answered in the past. To my reading it is basic common sense that some ongoing discussion is still in progress, and that the forum has a sub-section for plumbing related questions. (read the title of this forum section "Plumbing & central heating free advice"), so all is in order and good.   

So to answer your question: Your comment about dentists and eyes suggests that Luke is asking the wrong question in the wrong place and will get the wrong answers. In this instance you are the one who is wrong. So that is what is wrong with that. Your key input to this thread so far consists of stating that you have nothing to say, as it was outside of your skill set. Which is just wasting forum posts and is only marginally different from general Spam. e.g. posting no relevant comments to seek attention. At this point in time I am minded to give these off topic posts a few hours after which I shall de-clutter this particular thread to keep it on topic.  Just to remind you of a basic forum concept:-

If you have nothing to say, You do not need to post "I Have Nothing To Say". The rest of the forum members are intelligent enough to realise that those who haven't posted comment have nothing to say!

Doc H. 
 

 

[Doc Hudson]

Nope, tried to modify my foot pump to give a good seal on the header tank outlet but didn't quite get it, and bubbles just came straight back, I will try again tomorrow - If I can get a good seal I could give it 4 bars of pressure, think that would help?

Will try this tomorrow.

For now I've sealed everything back up to have what's left of my weekend to get ready for the week!

I see this as an ongoing battle so any other thought or questions, let me know and we can talk them through.

Luke

Firstly. I wouldn't have drained the system to check the flow at the valves.  As it is very easy to remove a radiator without fully draining a system.  e.g. With both of the radiator valves in the off position the valve lock nut connecting the radiator (at the same end of the radiator as the bleed valve) can be loosened and the water released in a controlled manner into a suitable receptacle , (could be a small flexi tub, Tupperware box, paint tray etc.), by using the bleed nipple as a control to the outlet flow. You would then have known that the rest of the whole system (flow & return pipes) was still full of water. At which point opening the valves into a tub, should have given near equal flow.

Anyway:  I wouldn't pursue the header tank option.  If you say all other radiators worked previously and one pipe at the faulty radiator had a good flow coming out but the other didn't, then that is where you need to concentrate your efforts. I would try again with reverse air pressure back up this pipe. Did you get a pressure gauge and pipe connector with a suitably sized connection that you can screw directly onto your suspect rad valve pipe? If so I would try more pressure down the pipe.

It is possible that the pipe is physically damaged, (kinked or squashed somewhere during installation), and that it has never worked properly sine the day it was installed. In which case its a lift floor and replace. Personally I hate micro-bore pipework, 8mm or 10mm,  keep to 15mm minimum it's far more reliable in my opinion.

Doc H.

 

[Evans Electric]

I may be talking ballcocks  but I'm wondering if the flow & return are crossed at your rouge rad .

Presuming theres a thermostatic valve on the flow side ,  perhaps it won't allow water to pass in the other direction .   :C

I put my own heating in years ago with a header tank supply....I  had a modern boiler fitted and noticed that the flow and returns are reversed so hot water enters the rads at the original return side.    I think theres a reason for this  but can't remember it now .

I'm presuming both your valves will  open fully , specially the thermo one which may be stuck in the shut position .

I do know that micro bore systems heat up really fast  but can be prone to blocking with sludge 

 

[Rob_the_rich]

Firstly. I wouldn't have drained the system to check the flow at the valves.

yeah but, the OP had already checked the flow rate from both valves after removing the rad and found one valve to be only passing a dribble. I thought that by draining just the pipework, with all rads shut, it would remove the pressure behind any blockage so that pumping air or water up the valve might shift it. Admittedly, I did think that the system had been drained down before when I suggested it, but the OP had not said that it was, my bad.

I may be talking ballcocks  but I'm wondering if the flow & return are crossed at your rouge rad .

Presuming theres a thermostatic valve on the flow side ,  perhaps it won't allow water to pass in the other direction .

It is possible. OP can please report back whether the valve with no flow is a TRV, and if so whether there is any arrows on it showing direction of flow. Modern ones have 2 arrows showing flow can go either way. But if TRVs were fitted, I think it would have been mentioned.

Going forward, the main problem now is that the system is not filling. This is either due to something from the tank blocking the filler pipe, or an air lock. Either way, all the working rads need the valves to be re-opened at both ends and bled, which I don't think has been done yet. It may be, if an air lock, that overnight the pipe has filled up with water, so hopefully it is resolved and we are back to finding out why one valve/pipe is not giving enough flow.

 

[Rob_the_rich]

Another thought, while it is drained, you could remove the valve and push some wire down the pipe. At least you will get an idea of how far away any blockage might be. Up to you whether you want to try this with a full header tank now, or after draining down again. Up to you.

 

[Doc Hudson]

Going forward, the main problem now is that the system is not filling. This is either due to something from the tank blocking the filler pipe, or an air lock. Either way, all the working rads need the valves to be re-opened at both ends and bled, which I don't think has been done yet. It may be, if an air lock, that overnight the pipe has filled up with water, so hopefully it is resolved and we are back to finding out why one valve/pipe is not giving enough flow.

I would agree, at this point we need to confirm that all of the rest of the system is still working correctly, i.e. no secondary sludge or muck dislodged in other pipework. But if the system is still drained I would try using the rising main water pressure back up the pipe from the suspect valve position first. I'd probably knock up a temporary arrangement to make a direct connection that you can put a garden hose onto with a local isolator valve to control the flow.

Take the valve off the pipe, then go 8mm to 15mm, 15mm to 3/4, 3/4 to garden hose connector, hose to garden tap, (assuming you have one??).

https://www.screwfix.com/p/c-x-c-couplings-15mm-x-8mm/45857

https://www.screwfix.com/p/male-coupler-15mm-x/82086

https://www.screwfix.com/p/hozelock-threaded-outdoor-tap-connector/52973

The outdoor tap connector will screw onto 3/4 thread of 15mm-3/4 converter.

Stick a 15mm isolator in the short 15mm section between the two converters.

https://www.screwfix.com/p/isolating-valve-with-handle-15mm/89226

You can now have an outdoor tap turned on ready to feed back up your pipe as and when you release the local valve. You should be able to hear if anything is flowing or not. If the restriction is so solid as to stop the rising main pressure I would think you are looking at floorboard lifting time. If this can clear the blockage then you can use the temp hose arrangement as a drain off point by disconnecting the tap and putting the other end of the hose into a drain to allow some of the muck to be removed from the system. 

When you are ready to refill I would start by leaving the dodgy rad off, (valves back on pipe and closed obviously). All other rads fully open everything, fill & run the system for a few hours and bleed all the working rads to make sure all air is out of the rest of the system. Then double check current state of the flow on the two valves where fault rad lives, before replacing the radiator. They should now be both approx equal.

Doc H.

 

[Luke Moreland]

It is possible. OP can please report back whether the valve with no flow is a TRV, and if so whether there is any arrows on it showing direction of flow. Modern ones have 2 arrows showing flow can go either way. But if TRVs were fitted, I think it would have been mentioned.

Correct, No TRVs - however once this is all resolved, I will be fitting TRVs to other rooms in the house, one step a time

I would agree, at this point we need to confirm that all of the rest of the system is still working correctly, i.e. no secondary sludge or muck dislodged in other pipework. But if the system is still drained I would try using the rising main water pressure back up the pipe from the suspect valve position first. I'd probably knock up a temporary arrangement to make a direct connection that you can put a garden hose onto with a local isolator valve to control the flow.

Yep, when I return from work I plan to start with bleeding the upstairs rads as per @Rob_the_rich's advice.

Is it also worth draining the boiler? I had to do this when I first refilled the system to remove air.

The current state of the system is as follows:

• New downstairs rad off wall and valves shut
  
• All other valves fully open
  
• Header tank full and not periodically filling
  
• I am unsure as to the state of each rad, in terms of water level, certainly how I left it last night was that drain-off was fully open and system was not draining (I was attempting to refill/flush the air from the system)
  
• I left the pump on max for a few hours, then put it to low overnight (it is mildy disturbing)
  

When I return from work my plan then is as follows:

• Put drain-off hose back on and open
  
• Bleed air from upstairs rads, to confirm circulation from header tank to upstairs rads
  

@Doc Hudson I have a hose from outdoor tap to 15mm which I've connected to my 15mm valve (which then gets compressed to 8mm on suspect pipe) and I delivered mains pressure to this pipe yesterday and it would not budge, atleast I didn't get anything out of my open drain, nor back into the header tank, water was not flowing.

Thanks,

Luke

Another thought, while it is drained, you could remove the valve and push some wire down the pipe. At least you will get an idea of how far away any blockage might be. Up to you whether you want to try this with a full header tank now, or after draining down again. Up to you.

I will see if I can grab something suitable on the way home later - i'll grab this https://www.toolstation.com/shop/p80592

 

[kerching]

Not had time to read complete thread so what follows may already have been said

microbore is a pain in the rectum for blockages, get the slightest ding in the pipe and it almost closes the bore. Most prevalent where it comes through the floor up to the valves. Have you checked this for 'Hoover injuries'?

instead of air, which could cause the present water "to ,hydraulic".   Could you use mains water pressure to try and clear any blockage?

on one job we were trying to clear a blockage....ended up that someone had fitted a non return valve to ONE rad and it had jammed shut...just a thought

 

[Doc Hudson]

I will see if I can grab something suitable on the way home later - i'll grab this https://www.toolstation.com/shop/p80592

I am quite sure that Toolstation item will no use on microbore pipe. It will be too big, its intended for 'waste' pipes e.g 32mm or 40mm plastic sink or bath type wastes, shifting blockages of hair, congealed soap etc.

Doc H.   

 

[Luke Moreland]

I am quite sure that Toolstation item will no use on microbore pipe. It will be too big, its intended for 'waste' pipes e.g 32mm or 40mm plastic sink or bath type wastes, shifting blockages of hair, congealed soap etc.

Doc H.   

Just grabbed it after lunch, it's 6mm in diameter, it could be close?

 

[Rob_the_rich]

I was thinking 2mm or 2.5mm steel wire. That 6mm snake might get stuck, and you don't want that.

 

[Luke Moreland]

I was thinking 2mm or 2.5mm steel wire. That 6mm snake might get stuck, and you don't want that.

I've got some coax cable which is pretty strong, around 2mm thickness, I could try that

 

[Rob_the_rich]

• ....how I left it last night was that drain-off was fully open and system was not draining (I was attempting to refill/flush the air from the system)
  
• I left the pump on max for a few hours, then put it to low overnight (it is mildy disturbing)
  

I would have shut off the drain point, the (air) blockage could have cleared at any time. You might be returning to a flood

Also, I would have switched off the pump after testing, it could damage it if running dry for an extended period.

These are some of the risks involved in trying to fix something over the internet.

If you had success before with getting rid of air in the system by draining the boiler, then try it. But since the pipes go up from the boiler, I doubt it will work, and any blockage might end up in the boiler. Might be best to leave it as a last resort

 

[SPECIAL LOCATION]

Only need to open each of the bleed nipples in turn at each of the high points in the system to get air out....

Water 'heavy' goes down...

Air 'light' comes up...

Bleed nipples on each radiator and at any strategic high points in the pipe runs..

maybe next to water cylinder if have one...

Screw bleed nipple on pump to clear and trapped in in pump..

etc......

Draining system will only put more air back in!

Never tried it....

but an electrical draw wire may go up the inside of 8mm pipe...

https://www.toolstation.com/shop/Hand+Tools/d10/Electrical+Tools/sd170/Draw+Tape+Nylon/p35379

But only as far as the first elbow!!!

:C

 

[Luke Moreland]

I would have shut off the drain point, the (air) blockage could have cleared at any time. You might be returning to a flood

Also, I would have switched off the pump after testing, it could damage it if running dry for an extended period.

These are some of the risks involved in trying to fix something over the internet.

If you had success before with getting rid of air in the system by draining the boiler, then try it. But since the pipes go up from the boiler, I doubt it will work, and any blockage might end up in the boiler. Might be best to leave it as a last resort

Sorry I wasn't clear, I did close the drain point overnight. Did leave the pump running on low overnight though, my bad.

Going to start investigating now.

Only need to open each of the bleed nipples in turn at each of the high points in the system to get air out....

Water 'heavy' goes down...

Air 'light' comes up...

Bleed nipples on each radiator and at any strategic high points in the pipe runs..

maybe next to water cylinder if have one...

Screw bleed nipple on pump to clear and trapped in in pump..

etc......

Draining system will only put more air back in!

Never tried it....

but an electrical draw wire may go up the inside of 8mm pipe...

https://www.toolstation.com/shop/Hand+Tools/d10/Electrical+Tools/sd170/Draw+Tape+Nylon/p35379

But only as far as the first elbow!!!

:C

The draining of the system would be just to prove I have no blockage from top to bottom.

Going to bleed the high points now.

Thanks

 

[Luke Moreland]

Ok.

There may have been a bit of user error yesterday  Guinness Drain rad inlet was tapped off. Meaning the tests with air pressure and mains pressure surely wouldn't have worked.

All rads in house now free of air and full.

Should I repeat steps from yesterday? (With the knowledge of my drain route being open)

1. Close all rads off - Open suspect pipe valve and shoot air in
   
2. Close all rads off, drain system and shoot air in
   
3. Close all rads off, drain system and apply mains pressure
   

Cheers,

Luke