Heatslave 25/32 No HW

[SJB060685]

I'd like to think that the position of flow switch is installed correctly at the factory and not an adjustment needed to be carried out by the installer, although it is a possibility I suppose. If him blowing on it connects the switch I'd say its probably ok and more like a flow problem. Are you sure you have flowing water, also what is incoming flow and pressure?

 

[SimonG]

I never assume the manufacturers get it right straight out the factory. Leaking joints, circuit boards, thermistors, missing bits, dented panels etc etc.

 

[ShaunCorbs]

I'd like to think that the position of flow switch is installed correctly at the factory and not an adjustment needed to be carried out by the installer, although it is a possibility I suppose. If him blowing on it connects the switch I'd say its probably ok and more like a flow problem. Are you sure you have flowing water, also what is incoming flow and pressure?

Ive seen / had them been put backwards before now so not registering flow etc

 

[SJB060685]

Ive seen / had them been put backwards before now so not registering flow etc

Boilers leave the factory wrong quite often but like I said I'd like to think the OP has checked all he needs before making the call.

 

[Ryooo]

Hi guys, I spoke to WB this morning. He seems to think there is a crossover. He advised the customer to isolate the cws to the boiler and crack the nut after the valve. If there is pressure there then that's the problem. Customer done this and has confirmed this.

Some additional information, the job is 4 1/2 hours away from me, WB engineer is based in Inverness 2 1/2hrs away and says its very unlikely to be boiler fault and more likely a Plumbing issue.

So know I'm thinking where it could be crossed. The shower is an old shower valve. It was previously a conventional system and it would have been cold water storage feeding prior to me changing it over to mains. Could it be passing at the valve?

What other checks could it be? Luckily it's my mate and he can isolate the shower to check this later.

 

[SJB060685]

So WB believes it's back feeding and preventing boiler from going through sequence when a hot tap is opened? Has the customer actually confirmed this? Did he isolate supply to boiler, drop the dead leg of water out and then crack valve open a little while later to prove it's back feeding?
If that is the problem then yes anywhere where the hor and cold mix could be the problem ie the shower, especially if it's an old gravity shower. Install NRV's on hot and cold to shower will prevent this and further problems, although its probably best replace the shower now that its mains fed.
What's the incoming pressure to the property? I would consider a PRV on cold main where it enters the dwelling .
Also, you say you're experiencing back feeding (or at least boiler not igniting when a tap opens) but tell me the boiler is coming on to heat the store?