boiler secondary heat exchanger

[rockinter]

Hi,
i was wondering if anyone knows of a combi boiler which doesn't have the new type of very small plate to plate heat exchanger?

We currently have vaillant boiler fitted in several houses, and the boilers have been fitted on existing system after being powerflushed. Some of them have been twice powerflushed by different people. They also have magnaclean twintech fitted. But still even after this soon as there is a small amount of sludge (basically like sand bit size) it builds up in the boiler and blocks up the boiler. I know in the old days the boiler hand bigger plate to plate heat exchanger so were less vunerable to small amounts of sludge.

So is there any boiler which has the bigger plate to plate heat exchanger?

 

[mickyg]

they've not been flushed properly. any boiler will suffer from problems if fitted to a dirty system, so its not about finding a boiler that will work with the contamination, but finding out why these systems are continually causing problems.

 

[rockinter]

i would have agreed with apart from the system have been powerflushed twice. Firstly this boiler person fits boilers all over the area he i very well know. Also the person spent a whole day doing it. Thirdly he used sentinel liquids. When the vaillant person came he said that we have to change our pipes because the dirt is stuck to the pipe. We even had a section of the pipe cut out and we can see, that it is black but very fine layer, you can only get it off by scratching it with a screwdriver. I even put it in ds40 acid to see if it would dissolve it but it didn't

i am not saying you are wrong, but then how do you find someone who can do powerflushing properly?

 

[Agile]

Thats the problem, powerflushing is not rocket science but to do it properly it is necessary to use the right techniques and chemicals.

Where did your fellow learn how to do power flushing? How does he choose the right chemicals?

What does he say about the dirt which is still in the system after he has power flushed?

What does he say about the dirt collected by the Magnaclean?

How much does he charge for power flushing?

There are several boilers using a different technique to get hot water. Vokera, Ravenheat and Intergas for example.

The Intergas is quite new to the UK market and installers have seen them at shows and will be likely to recommend them although i would say that they are too new be have been able to build up any reputation. The other two brands are not thought of as so reliable.

Tony

 

[rockinter]

Hi,
The system we have had flushed . The original person used x800 this was when he was fitting the new boiler. he used fx2 second time. he charges £400 per flush. apparently he is vaillants special partner or something, so they take him to trips to their factory in germany i think. He said first it was radiators, so we changed the radiators. then he said it is the pipes. But we haven't changed the pipes, as it will cost a lot of money to do. I have put the following myself, into the system, hyperflush fo 4 weeks. fernox cleaner for 2 weeks. but still after 3 months the heat exchanger gets blocked.

Now this is happening in several of the houses which all have vaillant boiler fitted. this never happened in the old days.

 

[Agile]

I have to agree that everything that you have said sounds as if it should be correct.

Many areas south of Oxford have quite hard water and calcium based compounds can form in the heating circuit and these are not seriously dissolved by any of the chemicals you have used.

You might try sulphamic acid DS3 as a trial. It is not very soluble and only works at a high temperature so needs to be circulated like that.

Dont greatly expect to clear a boiler plate HE by power flushing. Many engineers dont even know how to set the boiler to get the circulation through the plate anyway. They nearly always need to come out.

Its more labour intensive but a suitable gauze based filter will catch all particles rather than only the magnetic ones in a Magnaclean. I use a filter washer on the output of a Magnaclean.

Tony

 

[rockinter]

hi thanks for that.
i will give ds3 a try. i was just wondering can calcium deposit be black coloured? or are they usually white?

 

[Agile]

Many of the ones I see are grey and a cockroach brown.

They are complex compounds mostly containing some iron.

Tony

 

[gas4you]

Intergas don't use plate HE's

 

[Agile]

Dave hasn't read all the previous postings!

Been away on holiday Dave?

Tony

 

[gas4you]

No just horrendous work load, 7 days a week and mostly 12 hour days, except weekends and seems like it is going to be like this for the foreseeable future

TBH, couldn't bother to read through it all

 

[mehran]

Intergas, new to us maybe but not new technology. atmos has been selling them mass market for a few years now and at intergas HQ there is a 10 year old one showing that condensing for that long has done no damage to the hx.

few moving part
no plate hx to block
and about the only boiler to fully condense in hot mode(up 97% efficient)

so good I got one in my house

 

[rockinter]

this intergas sounds good to me. And it looks only slightly more expensive than the vaillant. How is their customer service if something goes wrong?
Also how much are the spare parts compared to vaillant?

Another question , has any one fitted a water filter on the central heating system?

 

[Agile]

No just horrendous work load,

So what happened to the four engineers you were going to take on in January?

So good I got one in my house !

So you got rid of the Heatline, the most reliable boiler in the UK, and fitted it for a customer then?

 

[mehran]

no

I had a floor standing WB 400 before it burst its tank. but I would still be installing heat-line solaris if they still made them. in fact I installed one of the last 18 months ago for a family member.

I been looking at starting to install intergas boiler for 3 years now. first when it was through atmos but the price performance balance was not right.

I like heatline solaris boilers because they were a no nonsense simple A rated boiler. and i like intergas for the same reason.