8mm microbore rad not getting hot

[Andy™]

not sure measuring resistance would help, its all soldered together so you will get a reading on all pipes, the difference between them will be barely different from the next pipe

 

[Rob_the_rich]

continuity between the two radiator pipes with rad disconnected

then between working pipe and manifold

then between dodgy pipe and manifold

what readings?

 

[Luke Moreland]

not sure measuring resistance would help, its all soldered together so you will get a reading on all pipes, the difference between them will be barely different from the next pipe

Very true, forgot about the big wedge of copper binding all these pipes together...

A magnet?

@Rob_the_rich I don't quite understand..

 

[Andy™]

you could try the wire again, get someone to keep moving it and you may be able to feel which one it is

 

[Rob_the_rich]

not sure measuring resistance would help, its all soldered together so you will get a reading on all pipes, the difference between them will be barely different from the next pipe

Yeah forget that then, just wanted some electrical tests.

Luke, best get the floorboards and carpet back down before you second pair of ears gets back.

 

[Sharpend]

Did you not say that water flowed through one valve but a dribble through the other, this would explain it. One pipe is still connected to the other manifold this pipe for what ever reason has been cut off and sealed? I'd go with cutting back the pipe and the leg from the manifold, at which point you will probably get some sludge from manifold. Stick a balloon over the valve and pump through the pipe then see if you get any blow back when you stop pumping, this way you'll have an idea if pipe is free. 

 

[Luke Moreland]

Yeah forget that then, just wanted some electrical tests.

Luke, best get the floorboards and carpet back down before you second pair of ears gets back.

I also have to put a door back on, and two cupboard sliding doors. I'm pretty good at dismantling things.

Now where did I put those screws...

 

[Andy™]

anyway, out of interest, why did you join and electrician forum and ask a bunch of sparkys how to fix a radiator instead of a plumbing forum?

 

[Sharpend]

anyway, out of interest, why did you join and electrician forum and ask a bunch of sparkys how to fix a radiator instead of a plumbing forum?

Have you tried to have a conversation with a plumber about doing your own fault finding and repair?? Not experienced the sharp intake of air through the teeth response? 

 

[Luke Moreland]

anyway, out of interest, why did you join and electrician forum and ask a bunch of sparkys how to fix a radiator instead of a plumbing forum?

I googled plumbing help - and this was one of the top few other than paid responses. I didn't read much into the fact it was on an electricians forum!

House is back in working order, minus a door.

 

[Andy™]

House is back in working order, minus a door and a working radiator

FTFY

 

[SPECIAL LOCATION]

So with this manifold that you have found....

Is it touchable.. by hand or accessible with a laser thermometer?

If so...

Before cutting anything..

Fill the heating system back up again..

Crank it up high.. make sure all the other rads are getting nice and hot...

Then check the temperate on each of the manifold pipes...

If one is a blocked one with no water flowing, then theoretically is should be much cooler than the rest???

I think ??

opcorn :C

 

[Sharpend]

In such a small space I'd think it unlikely that the manifold pipes will be of differing temp, particularly if the cut one is the only one left to feed the problematic radiator. 

??

 

[SPECIAL LOCATION]

I have assumed the option that its one of the connected pipes that is blocked,

rather than for some obscure reason at some time in the past on leg of the radiator circuit was cut, but the other half still connected...

Luke did say he had a flow of water out of the other pipe.....?

And as it does take time for standing cold water (and chunks of metal) to heat up...

if you can get your hands on those pipes where the blue covering is still on ...  or as far from the manifold itself... 

I would still have a shot at running the heating to see if the one pipe is cooler than the rest..

Or maybe with a non contact thermometer?

https://www.screwfix.com/p/stanley-stht0-77365-infrared-non-contact-digital-thermometer/8374j

Even with a 22mm three port valve you can feel the heat difference between the pipes relatively close to the valve body if set to heat only or water only,

when you have pumped hot water flowing through the others..

Its worth a shot for a short run of the heating before cutting open any pipes at random.

Guinness   

 

[Luke Moreland]

So with this manifold that you have found....

Is it touchable.. by hand or accessible with a laser thermometer?

If so...

Before cutting anything..

Fill the heating system back up again..

Crank it up high.. make sure all the other rads are getting nice and hot...

Then check the temperate on each of the manifold pipes...

If one is a blocked one with no water flowing, then theoretically is should be much cooler than the rest???

I think ??

opcorn :C

This was my logic, I've excavated some wall to get full access to the manifold, much to the horror of the Mrs.

So I started filling yesterday... an hour later, no hot water, no warm rads.

The problem is my boiler, it's reaching temperature, flow pipe is boiling hot, return pipe is cold, a few minutes later it's hitting its thermal cutoff and goes into reset.

Pump is running at max, so I'm going to investigate the 3-way valve, going to force it to open and see if I can get either hot water or heating working.

@SPECIAL LOCATION Yes I have flow from other pipe.

I've sourced myself a laser themometer and a thermal camera, I'm taking a half day from work to try get this sorted.

 

[Luke Moreland]

Manually setting the 3 port valve to open and calling for heating and hot water seems to keep my boiler operational.

Previously on auto I wasn’t getting a hit or even warm, it was cold, return pipe to the boiler.

I’m going to run the system for a while on max, keep everything circulating, double check rad bleeds, make sure everything heats up. 

Back to the manifolds in the meantime, one very hot, the other mildly warm, I’ll keep an eye on that. The hot one however, out of the pipes coming off it, one pipe is massively cooler than the rest. I can touch this pipe indefinitely whilst the others just a few seconds and it’s too hot to continue, so I think I have identified the likely suspect pipe.

 

[Luke Moreland]

All rads hot, I’ll address the mechanical valve issue after this.

Check the pipes out:

 

[Luke Moreland]

I took the chance and cut that pipe after draining the system, blockage is 30cm down into the ground, not really sure what to do next as the waste pipe cleaner I have is too big and the coax I have just crumples at it, I fitted a 8-15mm adapter to the pipe and poured some central heating cleaner down it.

Going to leave it overnight and check it tomorrow.

 

[Blue Duck]

Could it be metal, specifically ferrous metal from inside the rads? 

Neodymium magnet!

Or coat hanger with a fish hook shape on the end?

8mm is tight though!

 

[Luke Moreland]

Could it be metal, specifically ferrous metal from inside the rads? 

Neodymium magnet!

Or coat hanger with a fish hook shape on the end?

8mm is tight though!

Could well be, I'll see what I can grab.

It's frustrating, its about 10cm into the ground, looks like concrete... Replacing this is going to be a nightmare, I hope the cleaner works