Tepid HW & Rads - please give me a clue!

[bimbo117]

I am far from being an expert on such matters but i know something isn't right with my CH system and I can't face another winter wrapped up in 14 layers of clothes!

I have had my Baxi Solo 2 boiler serviced ever year since I had it installed approx 8 yrs ago, including last year when my problems started.

The boiler fires up for the 1st time in it's programme but shuts down again before either the HW or Rads get any where near the temp they should be. It also refuses to fire again during the 'on' period of the programme, although it can encourage it to have another go if I turn it off at the mains & reset the boiler. From this I am (hopefully!) correctly assuming that my pump is working?!

I live in a flat so all the Rads are on the same level. I have replaced the room thermostat & the control panel so don't think there is anything wrong with those. The thermostat on the cylinder is currently set to 70 degrees, although this seems to make no difference to the water temp. And bearing in mind that i am not an expert, am i supposed to feel some resistance if i moved the lever on what i think is the 3 port valve?

Although i know i am out of my depth I am reluctant to call in the company that service it considering they didn't seem to fix the problem last year! So all I ask is that someone give me a rough idea of things that could be wrong with it, so when I have to call the gas man in I look like i have some idea of what I'm talking about... so please, I am appealling to all you good and honest fitters out there to give me a clue!

Thanks!

Helen, cold but hopeful!

 

[oilman]

Hello Helen, I'm not a gas boiler tech, (hence the handle) but since you have tried replacing some of the thermostats thats taken care of them. It is likely to be a thermostat on the boiler or the boiler control board.

You SHOULD feel resistance trying to move the 3port valve lever so that seems ok.

To check the pump, you may be able to feel it vibrating, alternatively try altering the speed control on the pump (the only control) and see if the sound changes, or feel the pipes either side of the pump, they should be the same temperature if the pump's running.

Try these and let me know what happens.

 

[bimbo117]

ahh, orr err! i dont feel any resistance on the 3 port valve, but even if that is fixed, i assume that will not fix the water temp, i shall have to have a go at both i think.

i can feel the pump vibrating very slightly, but as the boiler is having one of its funny turns at the moment, i cant seem to encourage it to do anything!

but thankyou, you have given me lots of food for thought

 

[AL]

Does your boiler have any lights on the front? If so what are they doing, it might help to figure out why your boiler won't start up. does the boiler have a reset button, does this get it going.

Also do you have a manual for your boiler? If so these will often point you in the right direction and should have a fault finding guide. If not you could probably get one off the net?

Good luck

AL

p.s. i know nothing

 

[oilman]

That's a good idea, reading the instructions often helps

I mistakenly assumed from your first post that the 3 port valve was working ok. If there's no resistance it MAY be part of the problem as there's a couple of switches inside it. Though usually the pump will run and you will be able to heat the water though you may not be able to run the CH.

Do you have a service contract with the service company? If so, what level of service is it? When they come out to service the boiler how long does it take them? I ask this as my niece had someone to "service" her boiler and when he was about to leave (after 10 - 15 minutes) she asked him exactly what he had done, and the result was he was there for consderably longer servicing the boiler to the manufacturers instructions.

Depending on the level of service this might be covered but I understand your hesitating getting them out if they appear not to fix problems.

 

[AnonymousImport]

If your radiators are gettin slighty warm and the hot water is teppid then the 3-port valve is working. If you switch on heating alone then the lever should be completly free. The boiler and pump wouldn't come on if the other controls i.e. stats, clock, weren't working. My suspision would be the boiler stat (without looking for myself). If you turn it upto full the pipes as you know should be roasting. The stats do lose their calibration.

It could be a gas problem but as I say without looking I can't be sure.

Get a diferant company to look at it because if they say they fixed it and haven't how good is your service? They should be cleaning your heat exchanger and checking all the safety devices and burner pressure. The better companys have combustion testers. These tell you how clean the boiler really is and if it is burning safely. Minimum time of 40 mins.

 

[COG]

Your boiler sounds as if its reaching temp too soon, often from a lack of circulation ie sticking pump,air in system etc,.the boiler reaches max temp at the gas/water heat exchanger and the thermister shuts down the gas well before the system gets to temp,if you interupt the power you are basicaly re booting the board which is why it will re start for a short period, if the pump stops completely it would go to overheat but running slow or a build up of sludge will give what you describe,. If instructed how to test the pump speed do you have the competence to test ? and are you able to clean out your system?

 

[AnonymousImport]

A Baxi solo dosen't have a PCB or thermistors. It has a small board but this is the pump over run. Although I do agree with COG it could be the pump.

 

[COG]

Geting my models mixed up again, thanks for putting me right, now were is that baxi book.

 

[bimbo117]

ok, ok, you are all losing me here! i'm getting confused!

I took a chance & bought a new motor for the 3 port valve and fixed that in yesterday... resulting in guess what....'no change'!

i have also got hold of what i thought was a pcb for my Baxi Solo 2 ... but i now realise it is the control board that you are talking about. only paid £10.00 for it off ebay so no great expense lost! I havent changed that yet and i am beginning to get a bit confused as to whether i should bother doing that?

should i just be trying to remove sludge? or perhaps my pumps buggered?

You have all been really helpful and when i am standing in front of my boiler wondering why it hates me so much you give me the courage to keep trying to make the damn thing work... after all i just managed to exchange the motor on my 3 port valve all by myself! (that may not seem much to all you pro plumbers but it is to me!)

 

[corgiman]

I would say that boiler is overheating and shutting off

yep try the pump!! or bleed the rads

 

[bimbo117]

i have bled the rads, i'm getting water out of them - this is with the whole system turned off, so i assume thats 'ok'.

"If instructed how to test the pump speed do you have the competence to test ? and are you able to clean out your system?"

Pump test - i dont know, but i'll give it a go - what do i have to do? is this the thing where i unscrew the bit in the middle of the pump & see if the it is turning over too slowly? if it is i can have a go at that... i assume i should expect some water to be involved somewhere along the line?.. just so i dont panic straight away! and cleaning out the system, i thought i could just buy stuff that i pour into header tank that will flush it through?

why would my pump make any diffrence to the tap water heat? is it that the boiler is overheating cos the pump isnt pumping & therefore it shuts off before any water, be it CH or tap water gets more than tepid?

sorry for being a bit dim, but i like to try to make sense of things, that way i hopefully won't have to 1. ask you fab people again (creep creep!) or 2. look really silly if i bugger it up and have to call out an emergency plumber!

 

[oilman]

DON'T CALL AN EMERGENCY PLUMBER!!!!!!!! By all means call a plumber in an emergency, but if you try the first option, you may find you know far more than they do. (I have a sneeking suspicion you know quite a lot more than you're letting on. There's plenty of pro's who wouldn't change a valve motor for instance.)

Just a rough indication, which part of the country are you in? someone may know an ok firm to deal with if you get to that stage. (don't give away any info you don't want to.)

why would my pump make any diffrence to the tap water heat? is it that the boiler is overheating cos the pump isnt pumping & therefore it shuts off before any water, be it CH or tap water gets more than tepid?

If your boiler is a combi, the pump circulates water through a heat exchanger to heat the mains water that then goes to the hot tap.

Do you have a thermometer? (a thermocouple type or an infra red) or can you borrow one? or do you fancy a new gadget and want to buy one? If you had one of these you can measure the temperature of the boiler outlet pipe which will instantly tell you if the boiler is overheating, then you can measure the temperaturs round the system, which may give another clue.

 

[bimbo117]

lol, no honest i dont know anything really, but i have learnt at lot in the last week or so! my system is an 'open system' or at least thats my understanding of it i.e. its not a combi!

i live in Berks and i dont have a thermometer but i can always try to borrow / buy one.

someone suggested that a couple of whacks on the pump might shift it if it was sticking, which i have also done... perhaps a bit too hard as it appears to have now developed a very slight leak around the bit where it joins the pipe work...

perhaps i would be better described as an over enthusiastic amateur! i guess i will have to learn how to replace that as well now! whatever i have learnt has been from here, reading other forum answers and from tolerant male freinds, who have now described me as becoming a plumbing bore! what do they say... a little bit of knowledge is a dangerous thing!

 

[oilman]

Sorry if I'm telling you things you already know; with your type of system an inneffective pump will not pump heat into a coil in the hot water tank so the water to the taps will be stored cooler.

Never mind about a little bit of knowledge etc. if you carry on you could think about a career change (if you want one).

One post back you mention cleaning chemicals, they COULD help, but it's better to know what the problem is and if such treatment will improve things. A mechanical solution may be all thats needed.

someone suggested that a couple of whacks on the pump might shift it if it was sticking, which i have also done...

You may need a couple of big adjustable spanners to complement your big hammer. If it's a small leak, tightening the nut a LITTLE might stop the leak. Alternatively, close the valve on that side of the pump, undo the nut completely and smear some jointing compound round the olive then do it up again and open the valve. Just don't disturb the pipe when you do it, otherwise things may be a bit wet........

Taking the screw plug out of the end of the pump and giving the spindle a twist in the direction of the arrows might free it if it's stuck. (hitting it might not)