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

[DP]

Puma does DHW with no pump working.

Tony, I think the pump runs in a Puma for hot water unless I am mistaken.

If the differential between primary and secondary increases due to sluggish pump, primary sensors will bring on modulation or cause the burner to shutdown methinks, therefore, gas rate will be less.

 

[Agile]

The Puma pump SHOULD run on DHW but the boiler still functions even if the pump is failed. Thats why we get so many failed pumps when they first turn on the heating.

On DHW the modulation is controlled by the DHW temperature unless the primary flow reaches about 81° and then it modulates back.

Tony

 

[DP]

The Puma pump SHOULD run on DHW but the boiler still functions even if the pump is failed

I did not know that Tony, can you explain please?

 

[Agile]

I am not sure what else I can say about the Puma, Danny.

During DHW the pump is run in order to circulate the water in the outer part of the heat exchanger and give a more uniform heat distribution to the secondary ( DHW ) coil.

If the pump fails then as its operation is not monitored, the boiler still continues to give DHW without it and there is no obviously noticeable degradation of the DHW performance.

Tony

 

[fluff29]

Hi boys

Last question at the moment, getting 2 quotes this week. One engineer sounded quite switched on, will change the pipework to rad, fit drain tap, drain system, refill & drain again to see what comes out.

Is there any agreement on whether I should get 10mm or 15mm copper or is it bigger the better?

Tamz said 15mm, I am sure that DH said that if I only needed 10mm?? & if I fitted 15, it might give a path of least resistance and cause probs elsewhere.

1st price in of £246 + Vat to fit 10mm copper pipe & drain valve. Another £98 to flush hot water through the system and refill with inhibitor. No mention of a cleanser, is this common practice not to use a cleaner?
Thanks again.

Fluff

 

[Agile]

You seem to have chosen an expensive installer.

But it all depends on floors that need to be removed. If you can do that then the cost should be far lower.

Generally 10mm will be adequate if the pipe length is less than 6m per leg.

Tony

 

[fluff29]

Thanks Agile

Hatches already cut near rad. The run is less than 6m, so sounds good.

ta

fluff

 

[joop1977]

update?

 

[fluff29]

Hi joop

Got 2 possible good potentials:-

Get DP in to look at the boiler to see if there is any probs with it then look at any restrictions in the pipework. My option.

Local plumber - had a good look at system, listened to all that I did. He is suggesting repiping the prob rad straight off 22 mm pipe in 10mm. Fit a new downstairs manifold and repipe the pipe upto the upstairs manifold in 22 mm rather than the current 15mm. This is because the upstairs isn't brilliantly hot all the way to bottom of rads but is not a problem upstairs as the rads are oversized for the rooms. My husbands option althought I can see sense in this option and it would not do any harm, would just be the cost implications.

Just need to make a decision now and persuade my husband.

fluff

 

[bluey831]

Fluff - no doubt your powers of persuasion are every bit in line with your ability to decipher the complexity of the problem

And with that you will have the problem solved before 20 pages

 

[Agile]

I always charge for coming to diagnose a problem. Unlike the several people you have apparently had round free of charge.

BUT, I only charge if I have correctly diagnosed the problem.

If, as I rather suspect, there is a problem at the boiler then that might well be still there but largly masked by repiping your system.

The problem with microbore is that it only JUST works if everything else is in perfect condition. Put a little dirt in the pump and then it falls over badly.

Tony

 

[tamz]

BUT, I only charge if I have correctly diagnosed the problem.

You would have been out of pocket on this one then Tony

 

[Agile]

If there is a problem then I would have found it on site.

Its not possible to diagnose faults without the ability to carry out tests and observe the results.

With a flow problem a thermal survey will usually provide very valuable information.

Tony

 

[fluff29]

Hi all

Quick update.

Trying to get Alpha out to do the annual service.

Spoke to Alpha again, they are still pointing to a circulation problem.

I am keeping my fingers crossed that DP will be good enough to come through to the East and hopefully fault find the problem. He will be hailed as my savour if he fixes it.

Fingers crossed, this may all be over in the next month.


Fluff

 

[Agile]

I dont see what help it will be to get Alpha to do a service. Your problem is not one involved in servicing nor would the service engineer be very interested in diagnosing a circulation problem on microbore. Likely to shrug his shoulders and say "what do you expect on microbore".

Far better to get Danny to do a service if he is coming to diagnose the flow problem.

Dont you mean he would be your saviour? ( sic savour )

Tony