Replacing an immersion on a Megaflow

[Ropes]

Hi all, first post so go easy! I do alot of work in the local Mcdonalds stores, repairing leaks, replacing taps, unblocking wastes etc. One of the newer stores has a Megaflow fitted that has an immersion with a faulty element (as identified by an electrician). I'm going to replace the whole immersion, but i've never done this on a Unvented cylinder before only on a standard copper vented cylinder so would like some advice if possible.

I've heard Megaflow do a push-fit immersion type for some cylinders. It looks like it's threaded as I can see obvious way a push-fit type would stay in there, is it likely to be threaded or push-fit? (it's a 300 series, 6-8 years old)

Also, as it's in a Mcdonalds draining down/turning off the water is an issue so is the immersion in a dry well or will I need to drain down?

I've been a Gas Engineer/Plumber 9 years and this is the first replacement immersion that's needed doing on an unvented cylinder so I realise the questions might be somehwat basic but i'd rather go in to the job with slightly more knowledge than I currently have.

Ta!

 

[Agile]

I would not be going unless I was able to identify the actual fault!

Most that I have seen have been the thermostat, many just the manual reset tripped, and not the element. Although obviously the elements will sometimes fail.

As far as I can recall its just a screwed element but a different and smaller diameter thread from the standard element and much more expensive of course.

Tony

 

[Ropes]

I would not be going unless I was able to identify the actual fault!

Most that I have seen have been the thermostat, many just the manual reset tripped, and not the element. Although obviously the elements will sometimes fail.

As far as I can recall its just a screwed element but a different and smaller diameter thread from the standard element and much more expensive of course.

Tony

The fault has been identified by an electrician who has stated it's the element. The immersion is constantly tripping the manual reset. I am going on the advice of the electrician who's tested it more thoroughly than I was able to and McDonalds would like the immersion replaced so that's what i'm doing.

I can see that the thread is considerably smaller, roughly 2". Any ideas on having to drain down or not?

 

[giblets]

Yes, you will have to drain down to replace the immersion heater. As Tony said, the immersion heater is a special to the Megaflo and cost round about £100. You will have to specify the EXACT model/serial number of the Megaflo in question as there are different types. You will also need a special tool to remove and replace the i/htr. With regard to the downtime suggest that the job is done out of hours at premium rates.

 

[Slugbabydotcom]

A special tool is required.

Do you hold the card for Unvented Direct Hot Water supply?

If you are not trained in unvented cylinders you can not work on a megaflow!

 

[twgas]

if its tripping the overheat I'd bet its only the stat thats broken.

 

[Ropes]

A special tool is required.

Do you hold the card for Unvented Direct Hot Water supply?

If you are not trained in unvented cylinders you can not work on a megaflow!

I do indeed have my certificate for Unvented cylinders and was delighted to learn it will run it in July 08 after being told it would last forever when I qualified 4 or 5 years ago. It's surprising how few unvented systems there are (in my area at least), i've only been called on to look at 5 or 6 and this is the first that is heated by an immersion(s).

I'm interested in this special tool though, I take it this isn't required if it's threaded? I obviously have an immersion spanner but i'm guessing you mean a different type of tool. I'll look into it.

 

[Ropes]

Yes, you will have to drain down to replace the immersion heater. As Tony said, the immersion heater is a special to the Megaflo and cost round about £100. You will have to specify the EXACT model/serial number of the Megaflo in question as there are different types. You will also need a special tool to remove and replace the i/htr. With regard to the downtime suggest that the job is done out of hours at premium rates.

Thanks for your reply, we'll have to discuss having to turn the hot off with the manager and see what he says. It won't surprise anyone to hear how tight they are with cash!

I'm worried about the tool though, draining it is simple but am now worried I won't be able to get it out or fit the new one! Is the spanner only supplied with new packages or is there a slight chance one will come with a new immersion? I've given our merchant all the numbers that were on the unit and the heater so hopefully the right one will turn up.

 

[oilman]

McDonalds just want hot water. twgas has posted the likely fault. Electricians often get confused when water is involved for some reason. It tales about an hour to drain, and if it's just the stat, which is a 15minute job max, you could feature on Rogue Traders.

 

[Ropes]

McDonalds just want hot water. twgas has posted the likely fault. Electricians often get confused when water is involved for some reason. It tales about an hour to drain, and if it's just the stat, which is a 15minute job max, you could feature on Rogue Traders.

I'm fairly sure it won't take an hour to drain, the relief valve is fitted an inch or two above the immersion and the drain-off is already plumbed in to the waste pipework. It will take no more than 10 mins.

I'd be more than happy if it's just the stat and I will try this first but i'm fairly sure the electrician would have been happy too as he could've changed it himself and all would be done and dusted.

Say I overruled the electrician and got the stat and it's still not fixed. Who's going to pay for the stat and the labour to change it? Me, I expect.

Feature on Rogue Traders? for taking advice from a professional in another trade who's inspected a job and undertaking the work i've been asked to and that i'm fully qualified to do? I hope not.

I was just asking for advice on aspect I was yet to undertake in my years of experience. It's amazing how fast i'm presumed to be some kind of unprofessional goon. Internet forums ftw.