Central Heating Problems

[f1005705]

Hello,

I have a few issues with my heating/hot water system (not a combi boiler). House is 8 years old and uses an ideal boiler (house builders choice) pump wilo Gold drayton zone control valves. Microbore pipe. This will be the second full winter we have been in the house and it is going to drive me mad.

Issue 1

In the upstairs cupboard where the cylinder is there are two Zone control valves one for hot water flow to the boiler and one for heating flow. In the winter when the boiler is heating the hot water and the central heating come on there is a bang and water wooshes through the pipes as the Zone control valves change the flow (the hot water closes and heating opens)

See picture below. It's not installed sideways it's the way I took the picture

Untitled

• f1005705
• 11 Oct 2008
• 1

Issue 2

If the boiler is heating the hot water is for any longer than 30mins (on timer) then all hell breaks loose and the water 'boils' over into the overflow pipe outside and all the pipes bang and rattle (is this a problem the the cylinder stat).

Issue 3

When the heating is on you can hear the pump noise (hum) throught the whole of the upstairs (sounds like noise transfer through the pipes, however the downstairs is ok. I have bled the pump and rads.

Any pointers would be welcome. or do I need a new system??. The boiler is OK I have just replaced the fan.

 

[superdupergasman]

The first may be the valves are in the wrong way round...on ACL valves there is an 'A' and then a 'B' this is the direction of flow....

Second possibly boiler stat out of calibration causing overheat

or

Faulty pump sticking after a while

Third.....get a new Grundfos pump fitted, will solve the hummmmm
and maybe the banging!!

Good luck!

 

[namsag]

Isuue 1 both motorised valves are in back to front so this is prob reason for your bang

issue 2 your boiler stat has gone and needs changing as this could lead to a dangerous situation

issue 3 wilos can be a bit noisy and microbore may not help grundfos pumps tend to be a lot quieter

 

[leakydave]

I can't tell from your picture, but all looks ok, apart from as it's an S plan is there a bypass fitted fitted between flow/return pipes? I think there should be one.

What speed is the pump on? If it is 3 try turning down to 2... might quieten it a bit...

 

[weseeyou]

I agree that the boiler stat looks stuffed as it should shut down the boiler way before it kettles but shouldn't the cylinder stat switch the flow from cylinder to CH when the cyl reaches the required temperature ? maybe that is stuffed too

 

[f1005705]

Thanks for the replys so far.

I have changed the cylinder stat and that seems to shut the system down when water gets to temp (65C ish). I have also moved the dial (scale 1-6) on the boiler from 6 to about 5.5 to see if that helps, however this does seem to shut the boiler down if I move it below that (i guess the boiler water is at temp and indicated the boiler stat is ok).

The valves banging only happens in the moring. I have tryed to replicate it by switching on the hot water and then starting the heating and vice versa and can't get it to do it.

I think I will change the pump to see if that sorts it out if nothing it may make the system less noisy.

Any other help/ideas would be welcome

Thank again

Tony

 

[weseeyou]

might be worth looking to see if you can improve the pump fixing and pipe clipping .

 

[Softus]

shouldn't the cylinder stat switch the flow from cylinder to CH when the cyl reaches the required temperature ?

No.

If you don't understand how an S plan system works, weseeyou, then you really shouldn't be advising people on the subject.

 

[gas4you]

Can't really tell properly from your pic, but it looks to me as if the basic plumbing of this is all wrong. I certainly would never have plumbed it in in this fashion.

I also suspect that the vent pipe is closest to the pump rather than the cold fill?

Perhaps you could confirm this or not?

It would help if I didn't have to lay across my office desk to be able to view the pic at the correct angle

 

[simond]

What Ideal boiler exactly?

If it is a 'pump overrun' boiler then there is no bypass fitted. So when the valves are both shut there is nowhere for the heat to go.

This will cause the boiler to overheat and will also cause the pump to push against a static head, creating noise and eventually burning out the pump.

 

[Softus]

I've had enough of cricking my neck...

View media item 5378

 

[weseeyou]

Can't really tell properly from your pic, but it looks to me as if the basic plumbing of this is all wrong. I certainly would never have plumbed it in in this fashion.

I agree it looks a nightmare . I'd want to strip it out and start again. How could you ever balance a system in that configuration

 

[superdupergasman]

Configuration is all ok, Expansion, cold feed, pump.

Yes, no bypass, but thats not causing the problem here.

 

[weseeyou]

Configuration is all ok, Expansion, cold feed, pump.

Yes, no bypass, but thats not causing the problem here.

well it might be ok for you bud but I have never, and would never, install such an inefficient mess. That is not a designed system it is all just a confused afterthought

 

[Softus]

I have never, and would never, install such an inefficient mess.

It's certainly a mess, but what do you think is making it "inefficient"?