Can you buy core plugs seperately for…

[kroc_kroc]

…Potterton FF 55 boiler?

Just had my plumber around and he said rather than get a new Heat Exchanger if he can obtain them from his supplier or from Potterton directly it would save us a lot of money.

Also, if they can't be obtained is it better for me to buy a new bolier? I've had nothing but problems with this one. The heat exchanger was replaced a year ago by potterton and this happens??? Apparently, it's about £400 for a new heat exchanger so it can't be much more for a new boiler???

 

[doitall]

What make you think the hx has gone again

 

[kroc_kroc]

The heat exchanger hasn't gone – the core plugs have eroded (at least 2 of them). So rather than get a new heat exchanger I was wandering can we just get some new core plugs?

I'm not technical at all but the boiler was leaking water when I got home yesterday so i got our plumber over today and he tested by pouring water into the boiler and it was obvious it was coming from the core plugs.

I've heard that Potterton are renowned for having problems with heat exchangers so I'm in 2 minds whether to get a new boiler or not?
BTW

Had the system flushed when I had the last exchanger put in so I don't think sludge is the problem???

 

[doitall]

So what are you calling core plugs

 

[JohnD]

what corrosion inhibitor did you use?

were the core plugs factory-fitted, or put in by the person who swapped the exchanger?

 

[kirkgas]

you need to know the size in BSP and i'm sure you could get brass plugs but it will be a pig of a job getting the old ones out if they are corroded

 

[JohnD]

I've never done it on a boiler, but I've taken out some from machinery. if eroded you can sometimes wind them out by chiselling round the rim, or by drilling enough holes to make a slot you can hammer a tool into and use like a screwdriver.

if all else fails you can drill out the plug and pick out or tap out the remaining bits of thread

I am assuming the old plugs are machined off flat and have no hex or slot.

 

[kroc_kroc]

what corrosion inhibitor did you use?

Don't know? We used a company who spealise in flushing systems to do the work.

were the core plugs factory-fitted, or put in by the person who swapped the exchanger?

By the way my plumber was talking it's as if they would have come with the heat exchanger when it was replaced. He seemed confident he could get them out but has never purchased them before.

 

[arfurrrr]

you cant get the plugs , ring potty they`ll swap heat exchanger for £180 . or throw it in bin and buy something decent

 

[JohnD]

my questions were because it seems strange for plugs to corrode away quickly

I was thinking perhaps they had been incorrectly fitted; or perhaps there was no corrosion inhibitor added when the system was refilled, or perhaps both

If plugs had been fitted made of an incorrect material they might corrode very fast

 

[bengasman]

I have only ever seen one of these and it had rotted away completely destroying the pcb in the bargain. Piece of junk. Sorry op.

 

[Agile]

I think that these must be what I would call hex plugs, usually about 1¼" with a hex male head about ¾" across the flats. If so then they are standard plumbing components available at any good merchants.

I have seen them become corroded badly but I cannot offer any explanation other that the system has never been properly treated with inhibitors.

Tony

 

[JohnD]

they can corrode very fast if the metals are dissimilar, including different steels. It is much worse if the plug remains and the holes corrode.

I am told that on Type 42 Destroyers, the decks corroded around fastenings from the day they were built.

 

[ChrisR]

Same Q as Doitall, what are you calling core plugs?
Do you mean on the left and right ends of the casting?
These look like simple flat U shaped steel, bashed into place whereupon they go "over centre" and spring out to grip. They corrode like fury in cast iron - like they did in Leyland cars, given a chance. They are relatively easy to remove and come in lots of sizes off the shelf.
If you pop-rivet into the centre and pull, the plug comes back from over-centre with a pop and then comes out easily - ish.

 

[JohnD]

that's what I call "Welch plugs" not "core plugs"