Hello, pump problem?

[nick69]

Hi guys,

We have an 'Ideal Elan 2' boiler, its old but works very well. 5 Rads in the house, new Grundfos 15/50 pump. Well it was changed 1year ago. We dont have any TRVs on the radiators at the moment.

3 weeks ago the heating started to make a VERY loud humming noise that over powered the TV. Well after a few attempts finding the cause it seems its the pump. I changed the speed of the pump down to setting 2 and the noise was a bit better for a while (a few hours) then went down to speed 1 and it just didnt sound healthy so I put it back up to setting 3.

Ive searched this forum and no one seams to come back with their heating details for you I so never get a final answer.

Anyway, what would be the first thing to do to try and stop the annoying noise??
I plan on getting some cleaner and draining the system and refilling with that this weekend, then draining it and putting inhibitor in after that. Would this be a good start or is there a typical reason for this humming??

Thanks for your time
Nick

 

[Softus]

Top speed seems awfully unnecessary for merely 5 rads.

What about it sounded "unhealthy" when it was on the minimum speed setting?

Was an inhibitor added when the pump was replaced? Was the system drained and cleaned? Why did the previous pump fail?

 

[nick69]

The unhealthy sound at lowset speed caused the pipes to rattle like mad.

No inhibitor was added when the pump was replaced. The system was not drained and cleaned. The plumber didnt give any indication why the pump failed. Im guessing it seized??

 

[Softus]

Well, it sounds like you have a Saturday morning job awaiting you.

I would drain down the system (power off to the boiler and heating system first) to find out the state of the water.

Before you do this, take a peek into the F&S cistern, and, if it's not clean, then bale it out and get it spotlessly clean with a sponge and bucket.

When the system is empty, if you can take the pump head off its body (particularly easy with a Grundfos) then do that, and have a look at the state of it. If you're not happy with what you see then junk it and replace it.

When refilling, if the system was dirty, then you might want to introduce a system cleanser. This isn't entirely risk free, because you might remove sludge and rust debris that are covering latent leaks, but it's getting towards the season where you can afford to start finding out.

 

[nick69]

That sounds like a plan. Ill do that this weekend and ill let you know the outcome.

Many thanks for your advice
Nick

 

[namsag]

Ideal Elan is a low water content boiler and pump should be on speed 3 to get the water away from the boiler quickly they are sometimes ok on speed 2 but if you try and run on speed 1 the boiler starts to over heat and gets very noisy. Doesn`t solve your original prob but lets you know what pump should be set at. You could try adding sentinel x200 this stops a lot of boiler noises. Also although your pump is not old it could be duff

 

[nick69]

Ok thankyou. Ill flush it through and add a cleaner this weekend then see where we are.
The pump definatley needs new valves either side so ill change those when its empty.