Glow Worm 30HXi Helicopter noise

[vinayparmar]

The boiler is brand new only installed around a month ago.
System is clean with magnaclean in the return pipe work.

At aroung 55-60 degrees C a light rumbling/whistly sound start only to get worse the warmer it gets. it will finally sound like a helicopter above. the boiler does vibrate a little at this stage & it sound very unhealty.
It will never fail on any fault codes.
I have it downrated to 15KW and there are no noise problems & it purrs along beautifully.

Any Ideas?

Regards
Vin

 

[bell824]

in relation to your other post overrated boiler with innsufficient flow, you know the problem already!!!

 

[Agile]

Some people never accept what they have been told!

Tony

 

[bell824]

i will allow you that quick edit tony

 

[vinayparmar]

Hi, I have a grundfos 3 speed grundfos pump.
It was replaced with a new one when we thought it was a flow problem but it's not as the problem still exists. It been tried on all 3 speeds.

I have fully opened all rads on both ends of all the radiators to maximise flow through the boiler but no change.

Sometimes it starts howling from 1st switch from cold at 5:30 in the morning

It still makes a fair bit of uncomfortable noise even when it's range rated at 22KW.

I have 17 dads, 5 of them doubles. The system was running a glow worm 100F for the previous 25 years. The system is micro bore 10mm.
I only changed the previous working boiler to this one to bring my boiler into the 21st century.

I feel there is a problem somewhere. The glowworm engineer came to look at it and said the noise was down to the heat exchanger or sludge in the system. He drained a bucket of water from the system which looked pretty clean as it could be. He downrated it to 22kw but it still makes noises on full flame when it starts to get hotter. He said it may be something in the water making it foam.
He took away a water sample for analysis and suggested I drain the system 2-3 times, which I have done and it has made no difference.
I still haven't heard back from them yet. I did some if my own tests and put some water in my kettle and bought it to a boil, it didn't even foam slightly.
Hence the water in the system is ok (currently with no inhibitor)
Can it be the heat exchanger? Are these engineers any good?

Any ideas again

 

[mickyg]

you've got muck in your heat exchanger or lack of flow. Not the boilers fault. Where is the installer? you havent even mentioned him

 

[vinayparmar]

I rang glowworm this morning to find out the results of the water test, they are still waiting for it.
On their notes they have replace heat exchanger if water test reports ok.

How can you have a faulty heat exchanger on a brand new boiler.

I spent half a day flushing the system out several times and I have back flushed the heat exchanger. There is no problems with the flow rate and there are no impurities being flushed out.

Could there if been a batch with faulty heat exchangers and what sort of fault would you expect to have with a heat exchanger?

It still seems to me that the construction of the heat exchanger is too small for the size of boiler. Could it possibly have a smaller heat exchanger in there like for the smaller models available?

I'm stumped !!!

 

[Agile]

Who fitted the boiler?

Why was it so over specificied when an 18 kW would have been adequate?

If you want to get an idea of the flow then measure the flow and return temperatures at the boiler!

 

[vinayparmar]

The flow temp current with the boiler set on 15kw are as follows
When radiators are cold temp difference is around 20-30 degrees C
After heating been on for 1-2 hrs temp diff is around 15-16 degree.

I will check temp difference later when boiler is set to 30KW. If the boiler is too powerful I gather the temp diff will be much smaller.

What is the ideal temp difference I should be trying to obtain.
The Glowworm engineer who came to look at it did check flow/return temp when it was set to 30KW and he didn't think it was unusual.

Again I'll check the flow/return temps tonight.

 

[Agile]

15°-20° is ideal.

BUT just because you have set the boiler to 30 kW will notmean that its providing that power. In fact except at startup it will not!

 

[mickyg]

there's nothing wrong with the heat exchanger, its the same design as fitted to 70% of the boilers on the market. I have fitted loads of ultracom hxis and had a zero failure rate. However knowing the type of heat exchanger I always powerflush and fit a system filter.

You have poor circulation or contamination in your heat exchanger

You still haven't mentioned the installer and why he isn't dealing with this seeing as it's his job to make sure the system the boiler is being installed to is clean and with no inherent circulation problems.

 

[vinayparmar]

Hi, I got the installer back straight back the following morning after i heard the noise.
After serverals hours of trying to figure out what the problem was he said it was the pump. So I thought great at least it will resolve the problem.
The following day he spends a few hours draining the system and installed a new grundfos pump same model as the original that came out (a Grundfos 15-60 130.)
It didn't fix the problem, so I said the original pump must be ok so it back in.
He assured the pump was not pumping correctly and there was insufficient pressure.
He said they had flushed and installed the new boiler to specification and I would need to contact Glowworm.
I settled up reluctantly as I felt robbed, and now I have lost all confidence in their ability to put it right.
So I'm back with Glowworm stating if the water comes back clear then the heat exchanger will require replacement.

Many thanks to those who have replied

 

[Agile]

He assured the pump was not pumping correctly and there was insufficient pressure.

So how did he respond when he had fitted th new pump and itmade no difference at all ?

 

[vinayparmar]

As I said earlier he kept assuring me the pump was pushing correctly.
The pump was from memory replaced around 10-12 years ago and I thought at least it ond less thing to blame.
Ok I have a spare pump now.
I now know better to use another plumber next time I need one.