metal flakes in plate heat exchanger?

[scooter]

Hi,
I have these metal flakes that keep blocking up my plate heat exchanger and i cant workout where they are coming from or how to stop them?
The boiler is a Halstead Ace High combi ,so far i have fitted a Adeys Magnaclean to the return (after the last rad, close to boiler),power flushed the system and fitted a new plate heat exchanger but still they keep coming?
The heating works fine but the domestic hot water keeps running hot and cold and so i have to keep removing the plate heat exchanger and shaking out the black flakes of metal.
The boiler is about 5 years old and runs 10 rads and was working fine for the first few years.
I dont know why the magnaclean is not picking up the flakes(only picking up fine sludge)
Would they be coming from inside the boiler? im stumped!
Can anyone shed some light on this problem? its driving me mad
Thanks scott.

 

[stevetheplumber]

i would fit a strainer as well alwazs fit one size bigger than the pipe work and some isolation valves

 

[scooter]

Hey thanks steve, im open to all suggestions. Can you give a bit more detail please mate,what sort of strainer and where to fit?

 

[BLOD]

Which side of the phe are the metal flakes getting in to ?
If its the dhw side then the magnaclean won't pick them up.

 

[scooter]

The flakes are on the dhw side .

 

[BLOD]

Do as stevethplumber says and fit astrainer, fit it on mains supply to combi boiler to protect the phe.

 

[scooter]

What sort of strainer do you recommend? is it the same as a boiler buddy?

 

[WHPES]

Where is your water fed from? Mains? Private supply?

Is your mains fed from iron pipes?

 

[scooter]

Its from the mains supply (not private) , dont think they are iron pipe ,will have to check tomorrow, do you think if its iron thats where the problrm is?

 

[WHPES]

Are the particles magnetic? If so, I know it is unorthodox, but you could fit a Magnaclean to the incoming supply. I know they are for heating systems but I don't see why you couldnt use on that way.

You could be on a very old supply pipe and particles of iron oxide may be the problem (I see this somtimes round here).

Do you find that the loo and bath stain rusty coloured?

Otherwise, fit a particle filter to the incoming supply. A strainer will only pick up larger particles and may repeatedly get blocked.

 

[Puddle]

Can see the idea,will the Magnaclean work on mains pressure going though it and will it be ok inline under mains pressure?
Would go with the idea of a strainer on the incoming mains to boiler,your mains around there must be in a bad way

 

[WHPES]

You could check with Adey to find the maximum pressure rating for it.

Trouble with strainers (I assume you mean the inline brass type) is they only take out large particles and quickly reduce flow as they block up. A customer here had one and had to clean it every couple of days, so a filter was fitted instead.

A lot of old type ductile iron mains pipes round here. Makes a right mess of white bathroom suites.

 

[stevetheplumber]

you need to clarify which side of the plate heat exchanger is getting blocked either way a brass in line strainer will capture flakes always fit one size larger than the pipe its going on and valve it to allow easy cleaning
just ask for a brass inline strainer at any good merchants
its normally the heating side thats blocked you can tell which is which as the heating side will be blackened and mains side normally clean

 

[scooter]

Hi , my mistake it is the heating side which is getting blocked. Although the magna clean is fitted after the last rad and close the boiler,it seems to only collect the fine sludge and not the flakes (which are magnetic),.I was thinking of inseting some sort of filter inside the magna clean to stop them passing through the return. That way i can check it easily and if it collects any then the problem will be the rads (not from inside the boiler)which i can then sort out, although ive already done a power flush it may not have cleared everything? What do you think?

 

[WHPES]

If it is in the heating side, then disregard most of the previous posts.

I would take each radiator off and sluice it out outside using a hosepipe (somewhere where you can easily swill down).

If this doesn't work, You could try and reposition the Magnaclean or change it for the Magnaclean Twintech (has a wire gauze filter).

 

[scooter]

Ok thanks , seems that the wire gauze could be the way forward

 

[WHPES]

If you're still getting particles it would suggest that the powerflush hasn't cleared enough debris. The sytem wants cleaning properly.