never heard a noise like it

[Bobob123]

Hi All

I've just moved in to an old house and have got really loud pipes. When the heating is on there is really loud water rushing noises coming from pipes that lead down from the loft and in the airing cupboard plus pipes near the oil fired boiler downstairs.
I have a grant vortex eco oil boiler and also upstairs I believe the pump is a gundfos ups 15-60 130. Some of the radiators take ages to heat up. So my questions are:

1. what could be causing the noise? And what can i do to sort it?
2. the gundfos thing has 3 settings on it, it is currently on 3, what should it be on? And what does it actually do?
3. the hot water tank in the airing cupboard has its temperature set to 58. Is this the correct temperature for it?
4. the boiler has a heating temperature knob - should it be in a certain position?
5. I presume for the radiators I should just balance the system?

Thanks in advance

 

[dilalio]

Get a pro in to appraise the system... could be the first time it’s had proper attention for years.

 

[D_Hailsham]

1. what could be causing the noise? And what can i do to sort it?
2. the gundfos thing has 3 settings on it, it is currently on 3, what should it be on? And what does it actually do?
3. the hot water tank in the airing cupboard has its temperature set to 58. Is this the correct temperature for it?
4. the boiler has a heating temperature knob - should it be in a certain position?
5. I presume for the radiators I should just balance the system?

1. Go up into the loft and find the small tank. This is the Feed and Expansion tank for the heating system. There should be a pipe rising past the tank then looping over to exit above the tank. The top of the loop should be at least 450mm above the water line (which should be no higher than the middle of the tank when boiler is running). Is any water coming out of the pipe? If so this could be caused by a blockage or the pump is too fast. Turn the pump down to 2 and check again. If the flow continues, even on speed 1, you have a blockage.
   
2. The pump control sets the water flow rate round the system. It should be set to give a temperature difference between flow and return of no more than 20C at the boiler.
3. 58C is fine
4. The boiler thermostat goes between 65C and 75C. The lower the better as it will improve the efficiency of the system. Is there a room thermostat in the house?
5. If it needs doing; but sort the other problems out first.

 

[Bobob123]

Thanks for the response. The boiler was serviced before we moved in but would guess that the previous owners didn't want to report this issue to the guy as they were already reluctant to get the boiler serviced.

1. I've been in the loft and checked the feed and expansion tank. The pipe isn't quite 450mm above the water line, but about 250mm. No water is coming out of the pipe. No water was coming out so left the pump on setting 3.
2. The flow and return had a temperature variance of 23C. Do I need to alter this?
3. Noted
4. I've changed the thermostat on this to the lowest setting. There is a thermostat in the hall which seems like a silly place as it is the coldest place in the house due to insulation issues that I am fixing.
5. I will bleed all radiators first just to check no air in the system.

Any other ideas about what I might be able to do to get rid of the loud gushing noises?

Thanks

 

[D_Hailsham]

1. Is that 250mm to the exit or to the top of the bend? It's the distance to the top of the bend which is important ( I may not have made that clear).
2. Turning the pump to a lower speed will increase the differential, so leave it on 3.
3. Noted your noted
   
4. Turning the boiler down is OK provided the house gets warm enough. But if you put the wall stat in the warmest room it will turn the boiler off before other rooms have reached temperature. If the hall is taking a very long time to heat up then the rad may not be large enough.
5. Bleeding should be done when the boiler is off, and preferably when the water is cold. Downstairs first, then upstairs.

It might be worth bleeding the pump (undo large silver nut in the centre and wait for some water to come out). Also check that the spindle turns easily.

What is the PC of the pump (on the front plate)?

 

[Bobob123]

It was 250mm to the exit.
The PC is 0414

Thanks

 

[D_Hailsham]

It was 250mm to the exit.
The PC is 0414

As long as it's at least 450mm to the top of the bend, that's fine. (The water will expand in the pipe when heated; we don't want it spilling over the top of the bend back into the tank.)

The pump was manufactured in 2004, week 14; so it's not all that old. But that doesn't explain why you have such a large temperature differential - unless the pump's impeller is faulty. This would mean dismantling the pump (shut valves and undo 4 allen screws).

 

[Bobob123]

Thanks for your information and help. Turning the boiler thermostat down seems to have done the trick. Will monitor over the next week.

 

[DaveHerns]

Blocked feed and expansion pipe and/or pump impellor full of sludge? I've had similar problems