New Heat Exchanger - Seems less flow

northernsoul

I have had a new heat exchanger fitted to my 3 year old Vailant Ecotec plus 837. It started making 'whuring helicopter type noises ' when running hot water on full. Everybody including my plumber thought it was the fan or bearing. British Gas first gave it an ultrasonic clean, which did not improve things, then replaced the heat exchanger, which solved the problem. I had a whole new system but they said black water came out. They said it cannot have been flushed correctly on installation, but, as far as i know, it was. I may be wrong but the hot water flow seems less. I get 15 Litres/min from cold water bath tap but only 9 Litres/min from hot water bath tap. Could they or the new heat exchanger have changed the flow rate, so as to make the boiler work less hard and therefore make no noise. The hot water flow rate of the Vailant 837 is 15.2 Litres/min

jalexa

northernsoul wrote: »

They said it cannot have been flushed correctly on installation, but, as far as i know, it was.

Who did the installation? Is there a record of inhibitor added?

Canucklehead

northernsoul wrote: »

I have had a new heat exchanger fitted to my 3 year old Vailant Ecotec plus 837. It started making 'whuring helicopter type noises ' when running hot water on full. Everybody including my plumber thought it was the fan or bearing. British Gas first gave it an ultrasonic clean, which did not improve things, then replaced the heat exchanger, which solved the problem. I had a whole new system but they said black water came out. They said it cannot have been flushed correctly on installation, but, as far as i know, it was. I may be wrong but the hot water flow seems less. I get 15 Litres/min from cold water bath tap but only 9 Litres/min from hot water bath tap. Could they or the new heat exchanger have changed the flow rate, so as to make the boiler work less hard and therefore make no noise. The hot water flow rate of the Vailant 837 is 15.2 Litres/min

What is the HW flow rate from the kitchen tap? Rate from other DHW drawoff points? Did your 'installer' fill in the Benchmark? I recall your condensate thread...sounds a bodge. How much did you pay for the install? Has your installation been notified to Building Control? Does the install have a magnetic filter? e.g. Magnaclean, Magnabooster. Scale reducer?

Canucklehead

C_Mababejive

Poor system water quality and contaminants are DEATH to boilers like these. Has this been addressed i.e powerflush/water treatment/system design evaluation/sh%tcatcher fitted?

northernsoul

The installation was done by my long time plumber, who was 3 years ago, a member of the local Master Plumbers. He is not a current member. I assume from this that he is a good plumber, but maybe a member of any organisation does not neccesary mean anybody is good. He did make a mistake with the condensate pipe rising upwards through the wall. This was put right by him. There is a record/note on the boiler with inhibitor used. Will try hot water from Kitchen tap (the only other draw off point). No Benchmark was filled in. I paid £3000 for boiler and 7 rads with plasic piping. It took 5/6 days to install. I could not afford a magnetic filter at the time but think i will have one installed now. I do not see whether notifying building controls or filling in any paperwork makes for a good job, as just because the benchmark is filled in, does not mean it has been done, or done well. I thought i had a good plumber. I hope a manual flush will be good enough. My main question, though, was could British Gas (who i have a maintainence contract with) have turned down the hot water output ie is it adjustable. I am having an overhead 200mm shower head fitted (its limited to 12 Ltrs/min) so flow and pressure is important.
Doing everything to book, though, might show general competence

jalexa

northernsoul wrote: »

My main question, though, was could British Gas (who i have a maintainence contract with) have turned down the hot water output ie is it adjustable.

Measure the "gas rate" on DHW and compare with the boiler specification. Usually adjustable (as you suspect) but not familiar with your boiler model.

Edit: 5.93 in the installation manual refers.

northernsoul

Thanks for that Jalexa.. Says gas rate is set at prodution and does not require adjustment (but cannot see where it says how to alter it. This is obviously a job for a gas man and I might get it checked. I have seen my gas man check the gas meter with a pipe and gauge in the past.
Canucklehead, thanks for your concern. I have checked Kitchen hot water flow and it is about 10 Ltrs/min. The boiler is literally next door to the sink. Sink has a stop valve (10mm bore restriction when open i believe). Not sure about bath hot water tap, but i have asked my bathroom plumber to put no restriction on the hot water feed to the shower. Just trying to get the best flow and pressure to my shower for a good soaking (not bothered too much about saving water, want a very good shower!)
Do people think i should have a powerflush on my 3 year old system before i fit the filter or will a normal flush be okay?
What filter would anybody recommend?
Thanks for everyones help

gas4you

Fernox TF1

Canucklehead

O.P. : failure to fill out the Benchmark or notify the installation sets off warning bells for me. We use the Magnabooster2 or 3. Plastic pipes for CH should be barrier pipe...if your installer used non-barrier then system corrosion will result.

Canucklehead

jalexa

northernsoul wrote: »

Thanks for that Jalexa.. Says gas rate is set at prodution and does not require adjustment (but cannot see where it says how to alter it.

Indeed, but what I said was "measure". Use your gas meter. Take a meter start reading, start the bath hot tap on full. After a timed interval take the meter reading. Calculate the "rate" from the volume and time.

You do not need a "power flush" unless radiators have a cold spot at the base. Get the TF1 (or similar) fitted, do a manual flush ensuring the final fill is dosed with inhibitor. Prepare to be amazed when you check the TF1 after a month or so.

Pincher

A second vote for the Fernox TF1.

http://www.plumbnation.co.uk/site/fernox-total-filter-tf1-magnetic-filter/

I have two, love them. Don't forget it's 22mm OR 28mm. Check with your guy before buying the wrong one.

The only issue is where to position it, as you need space above to remove the rod, and space below to catch the dirty water. Also, you want to hide it, if it's in your nice fitted kitchen.

I clean the TF1 myself at least once a year.
It would be interesting to see what happens if I get a new plumber in. What are the chances that they will clean the TF1 without prompting?