warm radiator/ warm water / blockage / powerflush question

[12orange]

Hi All

firstly thank you for all being here and giving up your time to answer these queries

System: vented convetional Baxi 80PF boiler. Approx 10 years old. Radiators look to be about 15 years. Mixture of 15mm and microbore, though most are microbore. 20 radiators in house (!).

Problem1: hot water in ground floor and 1st floor bathrooms seem to trickle at times. Also shower sometimes goes from hot to cold in about 10 minutes, yet wasbasin next to shower has hot water.

Problem 2: 2 radiators downstairs only get lukewarm, 5 radiators on middle floor are warm and 1 not working (no heat). Top floor (loft) seems to have all working radiaors (15mm).

Problem 3: Recently the pump siezed so it was replaced. however, when it was replaced the system had to be backfilled. The problem with the radiators not getting hot was already there before the pump change. the engineer at the time said there is a blockage behind the hot water tank, which he couldnt get to as previous occupants had decided to build a shower on the side of it (1st engineer)!

Solution/Questions?

1. Are these all related problems?

2. I dont mind changing the Baxi boiler, but i do beleive in waste not want not. It is serviced every year (sadly by now retired engineer). but is it likely that the boiler cannot cope (80kbtu)? The 1st engineer certainly didnt mention this. I dont really want to go back to this 1st engineer as i wasnt around and he charged my wife £300+vat to change just the pump. Though in the end there was consolation when realised he had to backfill the system after changing the pump and he couldnt charge extra as he had given a fixed price in the first place - he was there about 2-3 hours - though initial of £300+vat was for pump and 1 hour work.

3. A 2nd engineer has said the system needs a powerflush. Although he diagonised this over the phone when i explained we had to backfill the system. I am happy to have the powerflush, i am assuming that the radiators are quite old and perhaps could do with it. Although when the system was drained (when fitting the new pump Grundos 15/60) i didnt notice any sludgy/black water.

4. Previous to the pump change, balancing was tried by, now retired, engineer and made a little difference but not much.

So i was thinking, should i go for the powerflush with the requirements that whatever happens the system must not be backfilled ie. the powerflush or any other action must sort the problem?

many thanks

PS I did read through the wiki questions, but i felt this one was about opinion.

 

[Agile]

It seems that you have multiple problems with your system and a competent engineer who has correctly identified the faults.

Unfortunately you dont seem to want to take his advice and have the problems sorted out.

It would be best to have the system repiped all in 22mm and 15mm and that will get rid of the filling problem as well as most of the sludging up problems.

It seems that you somehow expect us to confirm whats wrong with your system Without going there and charging you a diagnostic fee we only have what you have siad to go on.

All I can say is that he seems to have done a good job from what you have said.

Tony

 

[12orange]

It seems that you have multiple problems with your system and a competent engineer who has correctly identified the faults.

I havent had an engineer yet identify the faults, aside from the blockage. the other faults i listed are cobbled together from guesswork and this forum.

 

[12orange]

It seems that you have multiple problems with your system and a competent engineer who has correctly identified the faults.

Unfortunately you dont seem to want to take his advice and have the problems sorted out.

It would be best to have the system repiped all in 22mm and 15mm and that will get rid of the filling problem as well as most of the sludging up problems.

It seems that you somehow expect us to confirm whats wrong with your system Without going there and charging you a diagnostic fee we only have what you have siad to go on.

All I can say is that he seems to have done a good job from what you have said.

Tony

Sorry edited post by accident.

I dont know how i gave the impression that i didnt want to pay for diagnosic work, i have no issue with that. I am self-employed too, so understand it does cost overheads to come out.

I think it may have in reference to the 2nd engineer? I asked the 2nd engineer to come out, however, he declined. he said from the information i had given him he is certain the system needs a powerflush. He said i would be wasting my money if i paid him to come out just to tell me what he already knew from the phone call. Note that he has not ever seen the system. But, i am more than happy to go with the powerflush if someone can confirm that this is what they would do based upon the above information. again my apologies if i inferred i wanted a heating engineer to come and visit me for free.

 

[bengasman]

Need for powerflush is pretty safe guess, BUT no guarantees with microbore.
Personally I would only guarantee the 15 mm rads, and leave it up to you to pay for a try on the microbore or just replace them with larger.
Any rgi worth his keep knows the problems with open vent and microbore, and the old chap therefore did not do a great job.
No point changing the boiler until the other problems are sorted.

 

[12orange]

Need for powerflush is pretty safe guess, BUT no guarantees with microbore.
Personally I would only guarantee the 15 mm rads, and leave it up to you to pay for a try on the microbore or just replace them with larger.
Any rgi worth his keep knows the problems with open vent and microbore, and the old chap therefore did not do a great job.
No point changing the boiler until the other problems are sorted.

many thanks, it's a great comfort to know it is worth having a powerflush. I've read so many times on this forum that is it not needed at times.

Powerflush price seems reasonable, judging by prices on forum £500-600 for 20 rads.

 

[12orange]

I was also wondering this, i am sure there is an obvious answer,but i'm curious:

when radiators are filled through the vent pipe (backfilled), surely that means that there is a finite amount of water in the radiators? So, when the hot water/central heating divertor switches from hot water for washing, to providing water for central heating, does that mean the central heating radiators are replenished with water?

 

[bengasman]

water just circulates, it does not get changed