Worcester boiler issues ....

Fingers Mcginty

My condenser boiler has some issues. I had it installed 2 years ago and had a power flush done prior to install. I notice my rads don't get as hot as other houses I've been in. I had the heat exchanger changed out last year due to over temp issues. It was initially set to max but even after the heat exchanger was changed I had to ramp the temp down to 75 to prevent temp errors. I checked the copper pipe supplying heat to my system the at the bottom of my boiler and it's only reading 55 degrees on my meter even though it's 75 on the boiler display. What temp should it be? Any ideas folks?

DGOBS

Assume its still under manufacturers warranty.

Fingers Mcginty

DGOBS wrote: »

Assume its still under manufacturers warranty.

Yes it is

Fingers Mcginty

would people mind ;if you have the means; to check the temp of the pipe from the boiler feeding your rads. Mine is at 55 degrees even though the boiler is set to max. I have my cylinder stat set to 65 degrees so how will my hot water ever reach 65 if the temp of the water flowing through the coil is only 55?

Wearb

Fingers Mcginty wrote: »

would people mind ;if you have the means; to check the temp of the pipe from the boiler feeding your rads. Mine is at 55 degrees even though the boiler is set to max. I have my cylinder stat set to 65 degrees so how will my hot water ever reach 65 if the temp of the water flowing through the coil is only 55?

It wont. It can only reach 55C

Fingers Mcginty

exactly....that's what i was thinking. Must be an issue with the boiler?
Heat ex was changed out this time last year.

Wearb

Fingers Mcginty wrote: »

exactly....that's what i was thinking. Must be an issue with the boiler?
Heat ex was changed out this time last year.

I am assuming that the cylinder doesn’t have a separate feed from the boiler and a different feed for the heating. If they both have seperate feeds, then they both might be able to run at different temperatures. I am not familiar with gas boilers so I can’t answer with any certainty.

Fingers Mcginty

Wearb wrote: »

I am assuming that the cylinder doesn’t have a separate feed from the boiler and a different feed for the heating. If they both have seperate feeds, then they both might be able to run at different temperatures. I am not familiar with gas boilers so I can’t answer with any certainty.

No.... same feed

Dtp1979

So if your boiler stat is set to max, your flow pipe (the hotter of the 2) only reads 55?

Fingers Mcginty

Yes the flow pipe only gets to 55 when the boiler is set to 80 degrees celcius.
When i set it to 65 I'm only getting 45 degrees on the flow pipe.

Dtp1979

Fingers Mcginty wrote: »

Yes the flow pipe only gets to 55 when the boiler is set to 80 degrees celcius.
When i set it to 65 I'm only getting 45 degrees on the flow pipe.

How many rads do you have and what kw size is the boiler?

Pete67

Are you certain you are measuring the temperature on the flow and not the return?

Fingers Mcginty

Dtp1979 wrote: »

How many rads do you have and what kw size is the boiler?

4 bed detached house with 11 rads
bosch worcester greenstar 24i

Fingers Mcginty

Pete67 wrote: »

Are you certain you are measuring the temperature on the flow and not the return?

Yes definitely the flow pipe i'm measuring.
The return has a magnaclean so i know which is which

Wearb

Fingers Mcginty wrote: »

Yes definitely the flow pipe i'm measuring.
The return has a magnaclean so i know which is which

What's the temp on the return?

Fingers Mcginty

Wearb wrote: »

What's the temp on the return?

10 degrees lower than the feed pipe

Dtp1979

Fingers Mcginty wrote: »

10 degrees lower than the feed pipe

That’s a strange one to be honest.
Turn off all radiators and only heat the cylinder. Does the pipes heat fully then?
Other than that I’m wondering if the boiler kw output is turned wayyyy down in the settings perhaps.

Wearb

Have you added any rads recently? Or had the boiler derated?

Fingers Mcginty

It's the same when I'm just heating the coil in the cylinder.
I'm thinking that it is actually hitting 80 degrees in the boiler itself as it has gone over temp a few times and i had to reset it and turn the temp down to 75.

Fingers Mcginty

Wearb wrote: »

Have you added any rads recently? Or had the boiler derated?

No

Wearb

Have you tried another measuring instrument?

Fingers Mcginty

Wearb wrote: »

Have you tried another measuring instrument?

Yes I've used a fluke infra red on the supply and return lines and they tally up with my initial readings from my other meter.

Dtp1979

Fingers Mcginty wrote: »

It's the same when I'm just heating the coil in the cylinder.
I'm thinking that it is actually hitting 80 degrees in the boiler itself as it has gone over temp a few times and i had to reset it and turn the temp down to 75.

If the boiler is getting to 80 in the heat exchanger or is overheating then the flow pipe will be at that temp. It just won’t reach the rads. I wonder if somebody turned down the kw output when your first heat exchanger was acting up?

Edit. I assume you’re giving the boiler a couple of hours to heat up because some WB boilers have a function on start up that the boiler fires for 15/20 mins and dosent go above 45 degrees.

Fingers Mcginty

Dtp1979 wrote: »

If the boiler is getting to 80 in the heat exchanger or is overheating then the flow pipe will be at that temp. It just won’t reach the rads. I wonder if somebody turned down the kw output when your first heat exchanger was acting up?

Edit. I assume you’re giving the boiler a couple of hours to heat up because some WB boilers have a function on start up that the boiler fires for 15/20 mins and dosent go above 45 degrees.

But the flow pipe isn't at 80 ...I'm checking the flow pipe just as it leaves the boiler and yes the measurements were made after the boiler had been running for hours

Wearb

If it were an oil boiler I would suspect air or sludge in boiler at this stage.

Dtp1979

Fingers Mcginty wrote: »

But the flow pipe isn't at 80 ...I'm checking the flow pipe just as it leaves the boiler and yes the measurements were made after the boiler had been running for hours

To me it sounds like the boiler kw output is turned down. Therefore let’s say, the boiler is firing at 10% max power, so that’s never gonna reach temp.

Fingers Mcginty

Wearb wrote: »

If it were an oil boiler I would suspect air or sludge in boiler at this stage.

It's a gas condensing boiler. I had my system flushed prior to install 2 years ago. It was flushed again last march after the heat exchanger was replaced and it's just had another power flush. The system was clean but bosch recommended that as the first port of call.

Fingers Mcginty

Dtp1979 wrote: »

To me it sounds like the boiler kw output is turned down. Therefore let’s say, the boiler is firing at 10% max power, so that’s never gonna reach temp.

If that were the case why is the temp display on the boiler actually reading 80 degrees when it's set at max and then trips out for over temp?

Wearb

HX is getting to temp at the gauge but not at the outlet.....hmmmm

Fingers Mcginty

Wearb wrote: »

HX is getting to temp at the gauge but not at the outlet.....hmmmm

exactly

Dtp1979

Fingers Mcginty wrote: »

If that were the case why is the temp display on the boiler actually reading 80 degrees when it's set at max and then trips out for over temp?

Sorry. Long long weekend. Could be a combination. Of what I said or a faulty pump. I’ve seen those pumps go before. Not cheap either. Get on to the warranty

Fingers Mcginty

they changed the pump last week.
Up in a few hrs for work. Talk later and i really appreciate all the feedback lads.

Wearb

Fingers Mcginty wrote: »

exactly

I think at this stage (and as already been suggested) it's a warranty call.
They might be able to check to see if a proper flush was done, proper inhibitor added and no fresh water being introduced.

Fingers Mcginty

Wearb wrote: »

I think at this stage (and as already been suggested) it's a warranty call.
They might be able to check to see if a proper flush was done, proper inhibitor added and no fresh water being introduced.

Flush done 3 times already with rust inhibit added. No new water is being introduced as the top up valve is closed and it's maintaining 1.5 bar

Dtp1979

Fingers Mcginty wrote: »

Flush done 3 times already with rust inhibit added. No new water is being introduced as the top up valve is closed and it's maintaining 1.5 bar

Theres a chance you had a poor flush done 3 times. My money is on the pump though

Fingers Mcginty

Dtp1979 wrote: »

Theres a chance you had a poor flush done 3 times. My money is on the pump though

No they did it properly and the recirculation pump has been changed already.