New heating system weird behaviour

[WSB]

Have just had a conventional boiler and cylinder system installed with sealed central heating pressurised filler tank (rather than old style small header tank).

Had it a week and am finding that when the central heating is off but someone has a shower, the upstairs radiators come on.

The heating engineer has said that the system will settle but it's been a week now.

Everything except the radiators and the pipework to the radiators is new.

Lots of new pipework was put in place as was replacing an old back boiler that was situated in the living room.

I'm going to call him again but wanted to get a bit clued up on what could be causing the problem.

Any ideas anyone?

 

[Murdochcat]

Best get the installer back as that doesn’t sound right and they need to investigate at their cost

 

[fixitflav]

Have just had a conventional boiler and cylinder system installed with sealed central heating pressurised filler tank (rather than old style small header tank).

Had it a week and am finding that when the central heating is off but someone has a shower, the upstairs radiators come on.

Any ideas anyone?

The rads and cylinder coil are in the primary circuit, the shower in the secondary. It would be a big thing if they're cross-connected somehow.

Is it possible the rads get warm when running the shower causes a HW demand, so the boiler fires? Warm rads would then be caused if it's piped wrong, right way is all the rad returns must be commoned before the cylinder return tees in.
Is it just when showering, or any time the boiler fires in HW mode?

 

[gas112]

either a faulty motorised valve or he has messed up the final teeing in . NO it does not need time to settle in pure nonsense

 

[WSB]

Best get the installer back as that doesn’t sound right and they need to investigate at their cost

I will but do you have any suggestions what he could have done wrong?
Or what the issue would be?

 

[WSB]

The rads and cylinder coil are in the primary circuit, the shower in the secondary. It would be a big thing if they're cross-connected somehow.

Is it possible the rads get warm when running the shower causes a HW demand, so the boiler fires? Warm rads would then be caused if it's piped wrong, right way is all the rad returns must be commoned before the cylinder return tees in.
Is it just when showering, or any time the boiler fires in HW mode?

I think it only does it when the shower comes on.

 

[gas112]

I think it only does it when the shower comes on.

have you tried it when running a bath ?

 

[WSB]

Could it be that as the pumped shower is emptying water from the cylinder, the boiler is fired to replenish the hot water in the cylinder. All normal.

But there is some issue with the controls, telling the diverter valve to send hot water to the rads. Although, in this case sounds like the it's only opened enough to feed the upstairs rads.

When we see the issue, the digital control shows the central heating as off.

Can't help thinking that it's a stuck diverter valve,albeit a brand-new one.

Maybe it doesn't close off fully for hot water only. With central heating on and water heating, it's not noticed.

But when heating off and cylinder being filled with hot water there's some leakage due to not closing off properly, enough to heat the upstairs radiators. Given long enough, it might also heat the downstairs rads.

Or am I talking rubbish?

 

[WSB]

Turned out my theory was wrong. Heating engineer said he needs to come back and do some repiping.
Something to do with the towel rail in he bathroom. Don't quite understand though.
I know initially the towel rail came on with the hot water. Now it comes on with the central heating which is not ideal.
Apparently coming back this week to sort things out.
Don't know why he just couldn't have got it right first time....

 

[fixitflav]

Turned out my theory was wrong. Heating engineer said he needs to come back and do some repiping.
Something to do with the towel rail in he bathroom. Don't quite understand though.
I know initially the towel rail came on with the hot water. Now it comes on with the central heating which is not ideal.
Apparently coming back this week to sort things out.
Don't know why he just couldn't have got it right first time....

Thought so in #3! Give him credit for admitting he did it wrong.

 

[WSB]

Thought so in #3! Give him credit for admitting he did it wrong.

Didn't exactly admit he did wrong.
He actually said that Boxt will have to pay him more to come back and sort it out.
Don't see why they should if by the sounds of it, he cocked it up.
But not my money paying for him, so don't care.
Hopefully get him round this week.

 

[fixitflav]

Didn't exactly admit he did wrong.
He actually said that Boxt will have to pay him more to come back and sort it out.
Don't see why they should if by the sounds of it, he cocked it up.
But not my money paying for him, so don't care.
Hopefully get him round this week.

Be interesting to know what changes are needed

 

[ChrisJP]

It's good he is coming back to sort this out.
As for "give it time to settle", that's akin to salespeople in clothes shops when you try on something that's obviously too big saying "it'll ride up with wear sir"!

 

[WSB]

It's good he is coming back to sort this out.
As for "give it time to settle", that's akin to salespeople in clothes shops when you try on something that's obviously too big saying "it'll ride up with wear sir"!

Lol

 

[WSB]

It's looking like the issue was the lever on the diverter valve actuator was catching on the foam around the cylinder. He's cut the foam back now, so hopefully that will help.