Replacement radiator is colder at bottom than it is at top.

[Agile]

The lady told me it had never heated up and she had not called the plumber back. Not a case of balancing as the whole house was on microbore so I politely refused and advised her to get someone in to repipe the big rad to 15 mm.

I often see someone saying something like this and it always makes me wonder why they are not giving a quotation to fix the problem themselves instead of getting someone else to do the job.

Just read the previous posting.

This has confirmed that the TRV end is probably free but there was dirt coming out. Possibly previously blocking the pipe.

The situation at the return end is not stated very clearly. About 2-3 litres should come out of each valve if the system is pressurised to about 1.5 Bar and is operating properly.

An equal flow is expected from both flow and return ends.

I cannot comment on your boss because I did not understand what he was asking or why! Is he a heating engineer or a DIYer?

Tony

 

[Bahco]

I advised her to get someone in to repipe the big rad to 15 mm.

I often see someone saying something like this and it always makes me wonder why they are not giving a quotation to fix the problem themselves instead of getting someone else to do the job.

Probably because the punter won't want to pay a lot!

 

[mysteryman]

You have clearly identified the problem as muck, sludge and copper filings.

Keep on with what you are doing.

Microbore was OK when properly installed, and will continue to be OK if not blocked.

 

[fluff29]

Hi guys

Agile, will try to answer your questions. As we did not remove the rad from the wall, we could only pull the valve and pipe back from the rad, we could not get a bucket to catch the water. I therefore used a small plastic tub to catch the water when it hit the side of the rad panel. I therefore did not drain 2-3 litres. When I turned the return v/v on slightly, maybe a 1/4 to 1/2 turn, the water came out quick but it was not a large flow of water that came out compared to the TRV end. It more squirted out.

When we turned the TRV to III, the water came out quite quick, more a very fast flow as you would expect from a pipe but it did not come scooting out at pressure as the other end did.

I personally think that we should do the following:-

- Repipe the problem rad in 15mm pipe.
- Get the heating engineer to fit a draw off tap outside the house.

My husband and I will then drain off the system under pressure from the outside tap into a drain and refill. Repeating again until clear.

-If we still have problems, I will then get a powerflush.

I would rather get the powerflush after the new pipes have been fitted anyway so that I have a cleanish system.

Will a powerflush cause any problems with regards to loosening off v/v's, causing leaks to occur?

Also, how long does a proper powerflush normally take?

Thanks again for everyone's help. I really appreciate your time and words of wisdom. I don't want to do this job myself but get frustrated by local plumbers who have not even looked at the system in any depth or would suggest that they would do bucket tests, etc. They don't even put the system on to check it first before suggesting a flush.

Thanks

Fluff

 

[Agile]

Unfortunately I am still unable to come to any conclusion about your bucket test on the return valve.

Part of the process is to drain out about 2-3 litres which is about the volume that will be driven out by the expansion vessel if its properly set.

Its quite important thats pushed out with the valve fully open to carry out any dirt etc. and so the flow from each side can be compared.

If you cannot or will not take off the rad then usually the valve can be rotated 90° until it faces the room.

Is the heat-up any different after the bucket test?

Tony

 

[tamz]

Tony she would be just as well doing a stick yer head in a bucket test.
It never flowed well from the lockshield because it was only cracked open.

Fluff.
Don't waste your money on a powerflush. It won't work worth a hoot on 8mm anyway. Plumbers!? You just can't get the staff these days

As i said before re-pipe the rad in 15mm. That size rad will never heat on 8mm.

Get yourself
A roll of 15mm barrier hep2o. (grey plastic pipe)
1 x 15mm compression union.
1 x 15mm compression elbow.
4 x 15mm hep inserts
1 x 15mm Danfoss Ras-C combi pack (Trv and lockshield).
2 x 8mm compression stop ends.
1 x Sentinel X800
1 x Sentinel X100

That lot will cost you about £70 or so

Drain the system down. If you can't find a drain valve, take the stop end off after the ballofix (it is turned off with the slot across the valve and on when in line, 1/4 turn) and attach your new hep pipe to it using the union and run it outside. Open the ballofix and drain from there.

If you have no drain valve, get a 15mm compression tee and a 15mm MT cock and another 2 inserts. Run a pipe from the manifold to outside too. If you don't have a big drill to go through the outside wall, cut the corner off the nearest vent outside with a hammer and chisel and fish it in through that.

Lift a board under the dining room rad (you may need to lift one somewhere else too) and fish the new pipe through from the manifolds to the rad.

Cut the existing 8mm pipes and cap off with the 8mm stop ends.

Put the new valves on the rad, stick an insert in the pipe and tighten it on.

Remove the ballofix valve an connect 1 pipe to the existing nut and ring with a union (or tee if running a drain pipe). Remember to put an insert in the plastic.

Remove the stop end from the other pipe and connect the other hep pipe to there using the elbow.

Some foam lagging slid over the pipes would not go wrong when you are done.

When you are refilling it put some X800 either through the top of a radiator (towel rail is easier) or through the filling loop. Infact you may be better to fill it with water first, check your connections then drain and refill again with the X800.

Run the system for a week then drain it. Refill with water and drain it again then add X100 and fill again.

It is not difficult to do.

Btw It looks like an old FEP system from the 80's you have.

 

[Agile]

I recently fitted a new boiler to a system with 8mm microbore.

I was pleasantly surprised to find that the water was pretty clean even at first flush through.

I still treated it with X800 even so and after a week of that the effluent was still pretty clean.

Tony

 

[fluff29]

hi guys

going to do the bucket test again at least on the trv end to try and flush the system through again and will take off more water this time. Husband has hurt his arm so delayed at the moment.

If this doesn't work will get it repipe in 15mm and new draw off tap outside.
Can I get the plumber to fill the system with x800 and then we can drain it off in a week then flush through?

Read another post on a magnaflow. Would it be worthwhile me getting one of these fitted?

Also, I have a piece of lead pipe from the gas meter inside to the internal pipework. Gassafe engineer who disconnected my fire for me said that he should really remove the pipe but he never did any checks on it. Does it have to be removed? Could then get it done at the same time if necessary.

thanks again

fluff

 

[OLLIE20]

Loads of gas meters have a piece of lead coming off and then into copper as far as im aware there is no reg/rule which says it MUST be replaced if it is sound and not leaking, however is is advisable 2 replace with copper, but he doesnt have to do it, sort of made it sound like he was doing you a favour by leaving it, ;et us know bout the bucket test, this is the longest job in history

 

[Agile]

I would be more concerned about you doing the bucket test from the lockshield valve and letting a good flow rate ands about 3 litres of water out to ensure that side is free flowing.

You can always put a tube of some kind on the valve into the bucket.

Tony

 

[fluff29]

hi all

Have done the bucket test again on both valves. I used an orange b&q bucket which I never realised till afterwards is a 12 litre bucket.

We got good from from both flow and return. Did trv end first. There were a few black flakes but the water was suprisingly clear. It did have a slight blacky tinge to it but it is not very dirty water .(could post a picture if you want) The water flowed out freely and only slowed off for the last couple of litres.

The return end was the same flow but with only one black flake. Performed as described above.

We took about 5 litres from each valve, refilling the system in between.

There was no difference between each valve.

We put the heating on afterward, alot of glugging going on, will there be air in the system?

The heating was still doing the same thing.

From cold, the boiler comes on with boiler water coming down the flow pipe from the boiler for about 1 1/2 minutes. It then stops burning but the pump continues for about 2 minutes and the water from the flow pipe turns cold.

The boiler continues to cycle like this. Eventually the majority of the rads in the house heats up except for the big one. Some of the rads upstairs can be slightly luke warm at the bottom but we can live with this.

Any chance it could be a blocked manifold?

All thoughts on a postcard.

fluff

 

[scoobydo123]

When doing the bucket test did you manage to get the valve(s) fully open? I have used a builders rubble bag(doubled up) in the past to do the test as these get in awkard places.

 

[fluff29]

Hi scoobydo123

Yes, both valves fully opened. I cut off the top of a 1 1/2 litre coke bottle and worked perfectly. Tipped the contents into a bucket as we went.

fluff

 

[Agile]

Is the heatup from that rad still the same when used normally now?

If so what balancing has been done?

Tony

 

[fluff29]

Hi agile

The rad is still heating up (or rather not) the same as before.

I would say the problem is that the boiler cuts out too quickly and keeps cycling for some reason. The boiler only fired for about 1 1/2 mins before cutting out for 3 minutes. This keeps continuing. Obviously, all the smaller rads eventually heat up but there is never enough hot water circulating to heat the big one up fully.

If I turn all rads off but leave the problem rad on, the rad still doesn't get hot because the boiler just cuts out. Local plumber send out by Alpha said that the boiler is functioning properly and that it is a blockage.

Would it be worthwhile to get a powerflush?

Hot water gets to all rads, therefore can't be a full blockage in any pipe. But boiler keeps cycling.

I don't understand how there can be a blockage if water gets to all the rads and all the rads heat up either fully or just about fully except for the problem one.

Could this indicate a partial blockage between the manifold and the boiler and that is why the boiler keeps cutting out when it gets to temperature?

I have not tried balancing because the boiler keeps cycling just like it did when I first balanced it. I just wonder if I have been going down the wrong path as the pipework to the prob rad seems to be clear. I think the key is that the boiler does not stay on very long.

thanks again

Fluff