scale inhibitor?

stephssjr

Hi I need some advice please. My boiler has been playing up recently and according to the Npower engineer that came out today its because the heat exchanger is blocked with scale. Of course scale isn't covered by my boiler care and along with a astronomical quote said this is likely to happen again as we live in a hard water area. It has happened before and the nice BG man cleaned it for us as a one off but I would like to stop or at least reduce the chance of this happening again. I have been looking at in-line scale inhibitors, electronic inhibitors and filter inhibitors and am a bit lost as to whether they work or not and if they do which is best to have? I can not afford anything expensive so was hoping some nice person out there could give me some advice?
Thanks

gas4you

I always fit a scale inhibitor as standard on combi boiler installs, except Vaillant, as they offer a 5 year warranty against scale build up.

BUT, after saying that, I have never come across a plate heat exchanger that has been scaled up.

It has always been the system side of the plate that has become blocked with sludge/carp that has caused the problem.

What is the fault with your hot water and what make/model combi do you have?

manda1205

We had this problem with our worcester combi, we have a scale inhibitor fitted already, but we live in an extremely hard water area. We got a water softener in the end as it had only taken 18mnths to block the heat exchanger up with scale and it would cost around £200 for a new one, so after 4-5 years our water softener will have paid for itself.

southcoastrgi

manda1205 wrote: »

We had this problem with our worcester combi, we have a scale inhibitor fitted already, but we live in an extremely hard water area. We got a water softener in the end as it had only taken 18mnths to block the heat exchanger up with scale and it would cost around £200 for a new one, so after 4-5 years our water softener will have paid for itself.

but you have to be careful getting a water softner as some boilers state that they should not be used with artifically softned water, you need to check the boiler spec

Canucklehead

manda1205 wrote: »

We had this problem with our worcester combi, we have a scale inhibitor fitted already, but we live in an extremely hard water area. We got a water softener in the end as it had only taken 18mnths to block the heat exchanger up with scale and it would cost around £200 for a new one, so after 4-5 years our water softener will have paid for itself.

Hi: from WB 'Any water softening device installed must not be used to fill the primary water within the heating system.' More here.


HTH

Canucklehead

manda1205

Canucklehead wrote: »

Hi: from WB 'Any water softening device installed must not be used to fill the primary water within the heating system.' More here.


HTH

Canucklehead

We had Worcester out to fix the boiler (as its still in guarantee), the engineer was the one who told us to get a water softener as he said the inhibitors just aren't good enough. He did tell us if we ever need to re-fill the radiator system we should by pass and use hard water. As yet we haven't had to do this. So any softened water is just running through for the hot water on demand. (Its still hard water in the radiators from original install). The plumber who fitted the water softener also told us the same thing too.
What do people do when they have soft water though? Or is it just the artificially softened water that can effect them?

osiris100

I work for a water treatment company and one thing we dont sell are scale inhibitors. The reason being that they are so hit and miss. Sometimes they appear to work, sometimes they don't. The only real way to guarantee a soft water supply is to use a softener which you would need to feed with salt.

stephssjr

Thank you for your replies I'm sorry I had a family emergency hence the delay to my reply. I have a Halstead Ace High boiler which is firing for hot water (haven't tried the heating) but then cuts out after a few seconds (about 20 gradually decreasing over the shower!) so you get scalded and then frozen and then scalded again. The engineer said the scaling is a common fault with this type of boiler but I have googled the problem and found a site which suggested it could be the diaphragm that may have split so I have one on order to see if that's the issue. I have also read that the only way to stop scale is to buy a water softener but they are not to be used on boilers its all very confusing so I'm not sure what to do!???

gas4you

This is more than likely not scaling, but sludge/dirt in the system side of the plate HE. A very common fault.

If the domestic side was scaled you would more than likely get the boiler shutting down and locking out for an overheat fault.

Your plate needs removing and a simple chemical clean should fix it. Probably around £100 would cover it.

Double this cost for a new plate to be fitted.

I would have expected your heating chap to know this.

stephssjr

sounds about right, you know when you get that feeling that someone really doesn't want to do anything and is taking the easy most expensive option? I think I shall have to get someone else in.
Its so hard sometimes to know if someone is taking you for a ride, thank god for forums like this and people like you to help with the technical stuff!
I have got a spirotrap that sits before the boiler which I thought would protect it from sludge?

gas4you

In theory it should do, but in practice it takes such a small amount of carp to cause your problem, that it will occur with whatever magnetic protector you have fitted.

If yours is the old spirotrap thingy that doesn't have the magnet fitted, then I'm afraid to say that it is next to useless.

Magnaclean or fernox TF1 are the best for protecting a system, but sadly the magnaclean is not the best made IMO.