Help with a Baxi Solo 30 HE Regular

[M13KSP]

Hi All,

This is my first ever post as a newly registered gas safe engineer. I’m looking for help on an issue I tried to help with for an old couple that live locally to me.

They have the above boiler and very recently have had constant issues with it kettling and almost immediately locking out. The pump was very weak so I’ve replaced this for them thinking the issue was circulation and the new pump would resolve the issue.

As I’m posting here it’s needless to say that the issue still remains!!! Plenty of flow through all the rads and the cylinder but still the boiler ignites and locks out immediately. I’ve bled the whole system and bled the bleed pips on top of the flow and return pipes to the boiler, all good.

I’ve suggested that the heat exchanger may be blocked and they would be better off now getting Baxi in for a one off fix.

Is there anything else I should have done for them? I’ve handed them over to Baxi and admitted it’s beyond me at this stage, but for my own knowledge and experience could it be anything else?

Thanks for any help.

Mike.

 

[firemant]

Thanks guys, I checked the wiring when I replaced the heating 2 port head, they’re both opening up fine as I’m getting good flow upstairs, certainly through the cylinder in the airing cupboard as I can feel and hear it.

Blockage must be on the return I can only assume. I’m going to put some chemicals in the filter and run it cold for a few days, see if that frees anything up.

You keep saying you are getting "good flow". If there is "good flow", then by definition there is not an actual blockage.

The OHS is tripping. Therefore there is poor circulation. Suggesting a blockage. Ergo there is not "good flow". I fear that your perception of good flow is clouding your judgement, and causing you to assume too much.

Did you check the cold feed connection (assuming a header tank). this is by far the most common cause of this problem, in my experience. Sticking cleaner in a system with zero flow is probably a waste of , labour, time and cost.

 

[M13KSP]

My apologies, I’m not using the correct terminology. I mean that the pump is working well (I have changed it) and there is flow up to a certain point in the system, by good I mean that in the cylinder cupboard there is flow from the pump up to this point. So the blockage must be elsewhere. There is a header tank yes.

 

[Riley]

Also send @Harvest Fields @ShaunCorbs or @Riley your gas safe info as this thread keeps drifting in and out of gas safe only

 

[Last Plumber]

by good I mean that in the cylinder cupboard there is flow from the pump up to this point.

How do you know?
What are the flow and return temps on the circs?

 

[Riley]

I’m confused. When you say circulating can you prove the water is moving? Are the pipes getting hot? Or are you just feeling vibration through the pipes

 

[firemant]

My apologies, I’m not using the correct terminology. I mean that the pump is working well (I have changed it) and there is flow up to a certain point in the system, by good I mean that in the cylinder cupboard there is flow from the pump up to this point. So the blockage must be elsewhere. There is a header tank yes.

How do you know?
What are the flow and return temps on the circs?

Sorry, M, no one is trying to trick or belittle you. Are you new to plumbing, or just to Gas Safe? As per LP, how do you know there is good flow, as I thought no heat is leaving the boiler? You cannot "feel" the flow, apart from assesing temperture rises either by your hands or thermometer. You may feel some vibrations, but that does not mean water is circulating. You need to start from basics. the boiler is tripping on the 'stat (Yes, apparently). The 'stat is reacting to a rise in temp (sometime the stat or connections can be faulty, but in thos case you are reporting kettling (which, BTW, it probably isn't, it is overheating, which is slightly different), so we know the temp is raising at the boiler, evidencing that the stat is doing its job). That bit tells us there is a circulation problem - some sort of blockage/restriction. The fact that you have no heat to rads or hot water tells us that the problem is before the motorised valves or after the junction of both circuits, forming the return. (Do not start removing rads as per one of your early posts, that is a waste of your time.) The list of available suspects now becomes very limited. It boils down to: air, sludge or scale, or a valve

Air: are there any manual or Auto Air release bleed valves on a high point. Typically immediatly above the boiler, or in the A/C. AARV are notorious for sticking or leaking. Quite often, they are connecte with a compression nut - so you can carefully unscrew the nut below the valve to check for water/air

Valves: These are often inadvertently turned off, (or turned off, back on again - but without the spindle turning. Often a punter in a blind attempt to sort a problem will try various knobs) so you need to check. (I am aware this seems unlikely due to the occupants, but could a "freind" have been trying to help?

From experience: If there has been DEFINITELY no prior attendance by an "engineer", the A/C will be the location of such a valve problem, If there has been another "pro" in attendance, look at the F&R valves on the boiler. This is a prime area for a lever valve to be apparently in the correct position, but the valve being stiff locks in the closed position. A bit of effort moves the plastic lever, but leaves the valve closed. the same applies to Mag Filters.

Sludge or scale:. This, to the extent of a complete blockage, is actually very rare: I cannot recall seeing it occur, (on a heating system) TBH. EXCEPT (at a grave risk of being accused of repeating myself, at the junction of the cold feed and the system - have you checked this???)

You must relax, stand back, and apply logic. Talk to the occupants, (more often than not, I can ask 5/6 questions and be confident where the problem lies), but be aware that they are sometimes stupid, and sometimes lie

Years ago, I fitted a sytem in a "standard" house that was being renovated. Ages later, I was told a bedroom rad was slow to heat. I could not work out what the problem was, but it was no major issue. Until another worker lifted a floorboard, pulling out a nail that somene had hammered in (obviously never having heard of "pipes in the centre, nails on the edge"). It presented enough of a restriction to reduce flow to that rad, but had NEVER apparently leaked. Looking back, if we were all concerned enough to find the problem, logic would have forced us to find the problem.

Good luck