Pentair Mastertemp 400 Heat Coil Tube Sheet Assembly Replacement

Part #: 77707-0234

[@robertwilkinson73]

First off, thank you for doing this video! I’m a pool guy for 9yrs now, never had to change out an exchanger until now. So seeing it done was great info! I read thru most of the comments. I just want to give some tips to some people. If you are having heater issues and there is no code on the led screen, pop the top of the heater off, don’t shut it off or take any wires off, look at the control board. There is a row of error lights on the left side, if one is red see what the 2 letter code next to it is and google it. That will tell you the issue. The guy that mentioned about the check valve after the return line from the heater is 100% correct. I just want to add that if you have a salt cell you should have a check valve as well. The salt cell is just as corrosive to beaters as the chlorine feeders. If you are not getting an error code & no red lights on the back of the control board under the lid, open the front panel of the heater. Inside the square box (the lid flips down and might be held in place with a screw on the top right, open the box...look for my red error lights there as well. If no error lights, no codes in the lcd....take the very bottom bolt out of the black manifold there are 2 vertical rows of 6 I think, take the bottom one out on either side. If any water comes out...you need to rewatch this video because you need to replace the exchanger. If no water then the exchanger is not the problem. If you have a Pentair, Sta-Rite, Hayward..:it doesn’t matter, all the tips I have to troubleshoot will all work the same way. Heaters are actually very simple and there is not that many parts to them. Oh and very last tip & it may not be so nice but it’s very true. Your local pool supply store, I’ll use Leslies as an example, is an absolute rip off in what they charge for things. Buy from the internet to get the best prices. I shop at my local pool supply store that is only for pool professionals and give wholesale/internet prices. I’ve had to stop at Leslies on the weekends for emergency parts before & they should be ashamed at the prices they charge. Hope any of my input helps someone. Again, thank you for this video, I’m not rolling my eyes anymore, the repair I need to do isn’t going to be as bad as I thought, so thank you for teaching me how it’s done & done smart. My first thought was going to be taking each part off, not just the lid and keeping everything attached. That’s gonna be a huge help.

[@kw57rx8dr.9]

Except if the that exchanger is bad the heater is usually junk and should be replaced because it's likely throwing good money after bad given how much a new exchanger costs and the shelf life left in the unit.

[@kristopherpdavis]

Thank you for taking the time to share this. It saved me literally thousands of dollars that I don’t have. Thank YOU!!!!

[@pvt-pilot]

Great! Hearing that is exactly what makes it worth it to me to post this stuff. Cheers!

[@jamessieker1712]

So thankful you did this video. I am having a leak and am going to do an exploratory tearodown.

[@jbullock47]

Our heater stopped working and the pool service recommended a new one. Your very, very helpful videos have emboldened me to try to fix the one we have. Thank you! (And wish me luck.)

[@pvt-pilot]

Be bold, be stubborn, make it happen!

[@jzquad1]

Thank you so much for taking the time to produce this video and make life much easier for the rest of us!!!

[@mattwhipple191]

Great video. Followed the same process to fix my Mastertemp 250 yesterday. It had a smaller tube coil unit and it sat up on a spacer, otherwise the same. Only recommendation to any DIYer making the repair would be to remove the igniter prior to reassembling the unit. the second time (broke the original one) I put it back together, I aligned the top insulation pads, then dropped in the upper unit, lined up lid with the hole in the insulation for the igniter, then installed the new igniter. The igniter is only held in by two nuts and can be accessed without removing anything else so it was easy. Glad the kit came with a new one! Thanks again for the video.

[@BFSilenceDogood]

I have a 250 as well. How long did it take you to do all the work?

[@mattwhipple191]

In all, maybe a couple hours. However, I had a rusted bolt on the manifold that took a while to remove and the busted igniter added a little time. Overall worth the time in my opinion. Still working like a champ.

[@BFSilenceDogood]

@@mattwhipple191 That's fantastic. Thanks!

[@AquaTech225]

You saved yourself a good chunk doing it yourself an using eBay. I’m actually an pentair warranty tech/warranty center. So anything warranty and non warranty repairs. You definitely saved a good bit.

[@Icemarine972]

just had freeze damage on my brand new Heater in 2021 and this has helped me so much! thanks!

[@jeremybell3058]

You must live in Texas I am dealing with the same problem. I can’t get the coils or the manifold to replace

[@dextert.5524]

Were you able to replace the manifold and coil yourself? I have the same issue after the winter freeze

[@jeremybell3058]

@@dextert.5524 no I can’t find the manifold anywhere.

[@pvt-pilot]

@@jeremybell3058 www.ebay.com/itm/SWITCHDOCTOR-for-Pentair-Sta-Rite-Universal-Manifold-Replacement-Kit-Pool-Heater-/393314123442?_trksid=p2349624.m46890.l49286

[@dalebinning7375]

Best video I have ever seen......I had the same problem......It's now 2022 and the (6) coil exchanger is now $1,200. Only one tube was corroded away. I used a copper pipe coupling and JB Weld to sleeve it into the corroded tube. Fixed it!! I drilled a small 1/8" hole at the bottom of the tub as a drain to be able to verify that it's not leaking again.

[@pvt-pilot]

That's a clever fix. Remember you can always just take out one of the bottom 2 bolts on the manifold to verify that the tub is dry. Each bolt hole is a threaded tunnel all the way to the inside of the tub. If the tub has water, it will drain down to the level of the lowest bolt you remove. Small hole is a good idea also. I don't foresee anything being unsafe with a hole so extremely small. Good on you thinking outside the box.

[@loreall.2461]

I’m curious about something. We had a repair guy out to deal with the terrible exhaust odor on our MT400. He made some kind of adjustment that dealt with the odor, but when he closed it back up the heater kept shutting down. The heater was not shutting down before he was called. The adjustment seemed to have created the problem. He could not fix it. He just said there is a “hole in the tub” and recommended a new heater. He did not run any tests on the gas pressure. While the heater is an older model, I don’t understand the hole in the tub is causing the heater to shut down the entire unit. We have to leave a side panel off to keep the heater on to allow it to to stay on. He said it needed air.

[@fallosantis569]

this was a good video . thumbs up . it helped me a lot and showed me all the steps I needed. thanks

[@naturalstatepoolandspallc338]

so far I haven't came across one that was worth ripping into like that...its been so badly damaged or aged that we just recommended a new heater with a warranty. very good video!!

[@michaelcolon9739]

that was a great video. learned a lot thanks so much.

[@padilla7019]

Great troubleshooting and well explained video

[@mikebroderick6182]

Thank you. Very helpful videos!

[@synonyx]

Thanks for the video! Might have to do this myself soon unfortunately.

[@paulpowell4871]

Can't work on cars anymore so my pool heater steps in as a substitute. Thanks for the vids

[@splashman63]

I work on these heaters all the time and it is almost always the one I use for a replacement. You still have a problem yu need to correct I went through your videos so I could see your equipment and saw what has caused a couple of your heaters failures. There is no check valve at your chlorine feeder. With out a check valve when your pump is off the tabs continue to dissolve making the water very corrosive all the way back to the heater. Notice how all the tube ends are eaten away on one side thats the side closest to the feeder. If you don't install a check valve you will continue to have temp sensors, bypass and another set of tubes fail. There a special type of check valve to be used Pentair R172288 Corrosion Resistant Check Valve Best of luck and I'm sure your videos have help a lot of people

[@pvt-pilot]

Wow, I didn't think of it that way, but it makes perfect sense. I wish my pool builder knew that. I'll look into getting that check valve installed soon. Thank you for your input. That comment may help many folks on here as well. Cheers!

[@komits41]

@@pvt-pilot I have a Pantair Mastertemp125 with what I believe to be same heater coil failure because when I pulled the manifold bolt water came out. Someone else told me I too have a missing check valve which I will install weather I replace coils or replace heater. However, my question to you and Keith or anyone else would be if I install a check valve, how would you backwash? Do you also need to install some kind of bypass? BTW, PVT-POLOT, thanks for the great video! I would not have even thought about a DIY repair until I saw your vid. Thanks for the inspiration! :-)

[@pvt-pilot]

@@komits41 Hey Jeff, your pool plumbing should have 1 input and 2 outputs an minimum. (1 input from your pool, 1 output to your pool, 1 output to storm drain for backwash and rinse settings) If your spider valve is plumbed correctly, your water flow during normal operation will pull from the pool drains and flow forward through the filter, then onward toward the pool by way of the chlorinator. When you stop the pump, then move the handle to backwash, then turn the pump back on, it will still pull water from the same pool drains but the water will run backward through the filter and then bypass the plumbing going to the chlorinator/pool and go straight out to a storm drain probably in your front yard. So, if you had a check valve in line just before the chlorinator, running a backwash will not be a problem because the check valve will be between the spider valve and the chlorinator. The check valve would not feel anything during a backwash or a rinse because all water would be diverted to the storm drain output.

[@AquaTech225]

PVT-PILOT he’s 100% correct. That’s actually one of the things I look at if something will get warranty coverage or not when it comes to the heaters. Coils, and the sensors. If the extra chlorinated water leaks back from no check valve. And test the water and make sure the alkalinity is all ok and the ph ect. Though for sensors an the thermoregulator ect. I usually just cover. Makes no sense to nit pick with a customer like pentair wants. The exchanger I have to only because that part due to price has to be approved.

[@AquaTech225]

PVT-PILOT but their should be a check valve to keep higher chlorine leveled water from going back into the heater. Actually is a common thing I see. A lot of builders seem to not know. Or try an save as many bucks as they can by not putting it in. I guess in hopes the 3year warranty expires. Before a problem like that that they have to eat the repair bill for incorrect plumbing

[@Leoneidas]

Thanks for this. I ordered my replacement chamber and lid. I think I can work through it. FYI, if your chamber is rusted through, do not use high temp foil duct tape to repair, it will leak again and then melt the ignition module. Ask me how I know. Lol.

[@electroman982]

All bolts and nuts Never-Seez !!

[@ArmPump]

Not to be critical BUT the visegrips were on the gas pipe union backwards and no need for Teflon on the union threads as the threads are not the sealing surfaces. Looks good! 👍

[@ScottSellsSoCal]

Great video, thanks. I’m replacing my manifold due to short cycling and a rattling noise.

[@pvt-pilot]

You are replacing the entire manifold? I wouldn't do that. If you hear rattling (sounds like ice cubes bouncing around inside the manifold), that is a broken manifold bypass valve. It is very common for them to break because they are made if brittle thin plastic and can't put up with pool chemicals very well. (See other video on my channel on how to replace it)

[@johnstockel1174]

Well done 👍🏼

[@jcraigshelton]

Good video and explanation of the steps. I don’t necessarily think that poor water chemistry was to blame though. I mean, you got 8 years out of it which is more than most would get. The simple fact that you put a reactive metal like copper in the same neighborhood with a strong oxidizer (free chlorine), something would have to give sooner or later. 👍

[@swimking101]

Great video

[@markromero930]

I too think I had freeze issues. My 400 sounds like a compressor now. Loud humming noise and I can’t figure it out. Thinking the igniter was bad, I replaced that, the AFS switch, and the flue sensor. It tries to ignite, and actually did for about 1 minute before shutting off. I sure hope I don’t need an entire new unit.

[@cngautos]

Thanks for your video

[@DieselMike]

I just watched all your videos leading up to this. I give you credit. Most people would have sprung for a new heater at that point. Impressive. I came upon your videos because I am trying to trouble shoot my dad's non functioning heater. (exact same model as yours). He claims, other than the Pool LED light, nothing is working when he turns it on. The blower doesn't even cycle. "Service Heater" is lit up. But he can't tell me the diagnostic codes lights (if any) because he hasn't taken the panel off to look on the underside of the board. I'm heading over to his place later to check it out, but in the meantime trying to learn as much as I can about this heater so when I get there I will have an idea what's wrong.

[@carlosrios3723]

PVT-PILOT, agreed...a very helpful video and thank you. I'm still working on putting my pool back together after the winter storm here in Texas that cracked about every pipe and pump in our set up. Long story short, we had to bypass the heater due to a cracked manifold once we were able to find pumps out on the market. I'm now at the point of replacing the manifold to get the heater back up and running. Do you have any tips or "be carefuls" when removing/replacing the manifold? Thanks in advance.

[@pvt-pilot]

Manifold is external, so that part will be easy. Before replacing manifold, I wound recommend tearing the heater down to the coils as shown in this video and inspecting the copper tubes for cracks. If you have cracked copper tubes and a cracked manifold, I would recommend just getting a new heater. Repairing one or the other is cost effective, but not both considering you will still have no warranty at the end of your repairs. There is a manifold bypass valve in the manifold assembly too. If your new manifold does not have one included, be sure to savage that part as well as all of the sensors.

[@chiko82mx]

in 2022 I been replacing those heat exchangers for $2800 if heater is less then 5 years old. if is older I recommend to replace the heater..

[@stevengregoryphotography]

My coil won’t fit if I place first place the insulation soft insulation blanket on the bottom of the combustion chamber followed by the hard insulation board with the notch cut out over the lip of the combustion chamber. I see how this creates a perfect fit and how the hard insulation board then butts up flush against the face of the combustion chamber, but in my case, then the coil does not fit into that recessed area for it to align with the bolt holes for the manifold. If I pull the insulation and way and off that lip so that no insulation is taking up space in that recessed area of the combustion chamber, only then will the coil fit and align with the bolts with me having maybe 1/8” of play. Can you confirm you did in fact place the insulation on top of that lip in the combustion chamber per your note, vs having left it off in the video footage you shot? Thank you and others for any advice!

[@vickipowell8478]

First I want to thank you. The Video has been a great help. I've hit a sticking point. In you video you had a strap that held the top of the heater assembly to the tank. Mine had screws that held the lid down to the tank. I removed them and it appears that some sort of liquid adhesive is holding the tank to the lid. Ive tried to pry the lid off gently with no success. It appears the adhesive is holding it together. Have you seen this? Or has anyone else complained about a similar problem?

[@pvt-pilot]

I have heard of the screw lids, but nobody has mention separation problems with them. I am unfamiliar with that design.

[@shahryarfarhang200]

❤

[@ThePrimoBiker]

i do about 4 exchanger a month for work. its smart to take the igniter out before you slide the burner back in cause they are easy to break. the new exchanger kit should come with a new igniter and you can keep it as a spare.

[@pvt-pilot]

Very good information to know. Thank you for sharing your knowledge with others 👍

[@MichaelPolakTravelLife79]

How much do you typically charge for this repair. I have one coming up and am curious

[@augustalexander8179]

It would be nice to see the tricks on how you take things apart, clean them, ect.

[@pvt-pilot]

Agreed, I'll get a video helper on the next go at this. Watching me lift out and put back the entire upper half of the heater without disassembling any of it would have been a good addition to this video.

[@smaktalker]

Its also a lot easier just to get a floater with tabs and throw it in the pool

[@jimi1291]

Sick fix 😎!! Have you considered putting a check valve on the output pipe?

[@pvt-pilot]

Yes, I heard I need one between the chlorinator and the heater to keep heavily chlorinated water from getting back to the copper. Makes perfect sense 👌

[@andrewreutlinger9225]

Question for anyone that might have knowledge on the subject..can the 400hd coil be installed on the regular 400? Would this be an upgrade?

[@booneellis3404]

Hello, Sir! Great video. I followed your instructions to see if my coil or manifold had a leak, but cannot visibly see any cracks in either of them. The coil appears to be in good condition with little to no rust and still has all the tubes that connect to the manifold. Could it possibly be the face plat that is causing the leaks? Upon inspection that seems to have a few factures, but wasn't sure if water is even passing through the face plate. Please let me know!! Thanks again for your video.

[@pvt-pilot]

Try removing the top assembly without removing the manifold so that you can turn the pumps on and pressurize the pipes while still being able to keep your eyes on the pipes. See 6:13 of my video where I do this. Small cracks in pipes may be very difficult to see but much more apparent with water spitting out.

[@bbq4fun789]

Great video, very informative. Did you have a leak in the drum?

[@pvt-pilot]

Yes, copper tubes sprung a leak. Tub was full of water.

[@TheNYgolfer]

Great video. My Pentair Mastertemp 200 has this issue. The water is leaking out through the blower intake. I was wondering if that water is getting into the blower motor and damaging the motor.

[@pvt-pilot]

I think there is a bearing race between the blower motor and the fan blades. Bottom line, you need to immediately replace your coils. If you don't want to do it right now, you will at least need to disconnect the heater and put a pvc bypass between the two pipes connected to the heater.

[@TheNYgolfer]

@@pvt-pilot Thank you very much. I will repair it as soon as the kit comes in. In the meantime I do have it on bypass .

[@mikebroderick6182]

At 4 min. in, you mention that the old coil is 8 yrs. old. Is that 8 full years of use or 8 seasons of say, 3 mos. each? I have a 175,000 BTU heater that failed at one of the O-ring ends allowing water to get into the heater. My heaters is 3 yrs. old., but I actually use it 8-9 months of each year. And I monitor the pH and chlorine levels regularly. Also, when/if you winterize your heater, do you winterize it filled with RV antifreeze or leave it empty? I’ve been winterizing mine empty, but covered with a tarp thru the winter months and am wondering if I should be storing it filled with the RV antifreeze.

[@pvt-pilot]

I have never removed it from the pool plumbing. So even in the heat of summer, the pool water always runs through the heater coils no matter what. In the 1-2 weeks of freezing weather that we get in Houston each year, my Pentair panel goes into Freeze Protection mode and runs all pumps 24/7 while below 36 degrees. I was terrible at balancing my my water chemistry before this video. I have a weekly pool service now. I never wanted to bypass the heater because I can remotely turn up the hot tub while on the way home so it is ready for us when we get there. Can't do that if I bypass and drain the heater. If I don't think any winterizing antifreeze chemicals would be necessary if you disconnect your heater and drain the tubes. They are very short horizontally situated horseshoe shaped pipes as you can see. Just give the heater a little tilt with the manifold off to persuade the water to drain out of the copper tubes and call it a day. Great idea covering it while not in use.

[@phachan7145]

Great video! At the end where you put that cover ontop of the copper heat exchanger, it looked like styrofoam. What material is that?

[@pvt-pilot]

It is not styrofoam. It is a flame retardant material, hard and soft pads on both top and bottom.

[@stevenjacobs6934]

great vid...on another topic...there are some vids out there for natural gas applications where I never see a regulator being used on natural gas heaters neither at the heater side or the meter side... please advise?

[@pvt-pilot]

Now that is not supposed to happen ever. No gas service installation will pass building permit inspection without a regulator at the meter where I live. I would not advise it either. I have other secondary lower volume regulators on things like kitchen stove and water heater, but my outdoor fire pit and pool heater are straight pipe because they both need all of the volume the whole home regulator has to offer at the meter.

[@stevenjacobs6934]

@@pvt-pilot so I have 2psi coming from the meter running 25' through 3/4" pipe. I'm trying to figure out what kind of regulator to install at the 400,000 btu pool heater...heater calls for a minimum of 4"wc to 10.5wc Max. I'm thinking a maxitrol 325 5L. Bringing it down to .5 psi and adjustable 7-11 "wc. Any opinion???

[@pvt-pilot]

@@stevenjacobs6934 I have a 1" pipe feeding my meter and that is where my 1" regulator is attached. I then have a 1.5" pipe making the long haul across my property to the Mastertemp 400 and there is no regulator there. I don't know much about how to tell the PSI/volume the regulator passes, but I can post the info of my regulator label: Actaris - Model B-42 B42R-IRV ORI 3/16 7 0 IWC 1/07 (manufacturing date) Hope this helps

[@nowthatsfunny1]

I have the same heater. I'm having weird problem. The water is 74 degrees now. I turn the heat up to 90 degrees and it will eat until 83 then it shuts off. There aren't any codes and when the temp. goes to 82 degrees the check heater light turns on and then goes off....then it will fire back up and heat to 83. It will do this forever but never go past 83 degrees. I haven't checked the codes on the back of control yet. I will do this tomorrow. I've replaced the membrane touch pad, the control board below the membrane, I've replaced the flue stack sensor. Maybe it's the high limit switch but I'm thinking it is a water restriction problem but it confuses me because it shuts off exactly at 83 and no more, then restarts at exactly 82 degrees. Maybe thermistor but I would read a high temperature instead of a low one. I will fix it no matter what but I figured you might know better than me. Thank you.

[@nowthatsfunny1]

Thank you for posting these videos...they are really cool and you are one determined guy!

[@pvt-pilot]

Hmmm, no codes, short cycles with service heater light shutting down each cycle before achieving desired temp? That is screaming thermal regulator replacement. Watch my video on how to test it and replace if necessary: kzbin.info/www/bejne/aXa1nnh-nZ19Z9U

[@officerkrupke4966]

Increase your pool pump speed setting when in spa mode first before replacing anything. It sounds like it might be overheating due to low flow from pool pump.

[@JohnHastie]

Is this easy enough to replace as a DIY project? Is everything that is needed provided in the kit or are there additional seals etc that should be replaced at the same time?

[@pvt-pilot]

Mine did not come with any seals. I think they want you to put new high temp sealant compound on the red rubber seal under the steel band. That said, I just don't see the point and here is why...this is not a pressurized tub and there is no way any flames are getting past that steel band if you just put it back together like you found it. The combustion chamber has a massive 4" exhaust pipe confirming it is not pressurized. It also does not hold liquids, so a tiny leak or crack in a seal will not make a messy situation. So, sealant around the rim beyond the red stock rubber seal is just trivial. The 12 copper fittings did come with new O-rings to make a water tight seal against the manifold. That is great and very necessary. The process was very simple if you do it like I did...taking the entire upper half off in one motion without disassembling any fan, gas valve or ICM parts makes this super easy. Takes about 3-4 hours if you take the time to clean the mess in the tub thoroughly.

[@MRBIGDG1]

How old was that exchanger?

[@DanburyConnecticut]

great vid, can you elaborate on "this is why you should watch your chemicals"? what would cause all that corrosion?

[@pvt-pilot]

I did not measure my chemistry. I constantly threw large amounts of acid and chlorine at it when algae started to grow...all reactively, not proactively. Also, i do not have a back flow preventer installed between my chlorinator and my heater. No big deal while the pump is running, but when it is off, the copper pipes are very close to an unisolated source of corrosive chlorine. Chlorine is no joke for metals. Side note: do not store chlorine in you outdoor kitchen cabinets if you have them. I have Bull brand stainless steel doors (both sides). The fumes alone have destroyed the stainless steel doors on the inside. If I open them, the rust is top to bottom of each cabinet door because it is all same air space under to BBQ pit.

[@DanburyConnecticut]

@@pvt-pilot oh wow thanks for the info. Based on your knowledge in the vid I thought u were a service tech, but I guess this was your pool/heater. My chlorinator feeds inline to the pipe going back to the pool so I might be ok.

[@pvt-pilot]

@@DanburyConnecticut Mine is in line towards the pool from the heater too. It should be the last thing in line before direct shot to pool. I have just been advised over the years to put a backflow preventer between the chlorinator and heater. $80 prevention for $2600 heater. Seems worth it. ...and no I am not a tech. Lol, I'm an engineer in telecommunications industry. Just a pentair system owner that has seen enough trouble with their products to make a few videos from my experiences. Never thought I would have over 100,000 views from a few amateur videos about these heaters. Apparently I'm not the only one with Pentair heater problems. Hope they helped. If so, that makes it all worth it. ✌

[@fastbulletz]

Hey you have a black gas pipe going from the combustion valve to the blower. My MasterTemp 400 is a bunch of corroded pipe and fittings instead and was wondering where to get that and if I’m able to use one.

[@pvt-pilot]

www.ebay.com/itm/Pentair-Gas-Pipe-with-Union-for-Mastertemp-Sta-Rite-Max-E-Therm-Pool-Heaters-/232095955646?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l49286&mkrid=711-127632-2357-0

[@fastbulletz]

@@pvt-pilot thank you for the info. it seems like a rare part unless you buy it used with the gas valve. Also was wondering since I have fittings in my installation, theres also a gas orifice connecting. Where would this orifice be able to be added to that pentair black gas pipe?

[@paulabrilla5531]

I have a MasterTemp 400 that I have been troubleshooting since last year. I've check different foruns and looks like a common issue, but I have yet to see a resolution. Perhaps you can help. As soon as I turn the heat on, I see a 75 reading. It 'heat' blinks to call for heat and then steady light. It Ignites, air coming out of the exhaust. After about 5 secs it shutts off and temp starts counting up fast to 124 and then goes back to 75 and do the same cycle offer and offer again. No error codes on the front and no LED indicator lights on the back.So far, I replaced the thermar regulator, thermistor, a broken and just before opening the pool for the season, I replaced the bupass manifold. I found a rock in fhe by pass manifold so I thought I have resolved the issue. I was wrong. I also checked the blower. It was clean. No nest in there. Wires are intact. I'm getting frustrated with this. I don't want to buy and replace the control board because it's expensive and it might not be the problem. Filter is clean since I just opened the pool. The pressure is 20-25 psi, pump is running at 3450 rpm about 85gpm.

[@pvt-pilot]

I love to help people on here by sharing my past experiences. I would love to be of help to you too, but without codes, I can only suggest the thermal regulator and manifold bypass valve which you have already done. I have never replaced my control board, ICM, PS, AGS, AFS, blower motor, gas valve or igniter. I have replaced my bypass valve, thermistor, stack flue sensor, thermal regulator, high limit switch and heating coils and have made videos of each over the years. I am sorry that I can't direct you in any specific direction. It sounds like you have tried everything I know to try. Bummer.

[@mikebroderick6182]

You mention in the first 15 seconds about a previous video, showing the tub full of water. Can you provide a link to that previous video? Thanks.

[@pvt-pilot]

kzbin.info/www/bejne/noarq5p-p8hsfZI

[@dictumfactum7784]

You will always have this problem with this heater ! The tubes need to be straight

[@peterphelps7969]

You make some good videos I'm just curious as to what the repair bill was? Thanks!

[@pvt-pilot]

I have $600 in heat exchanger coils(eBay). I have $99 in replacing sensors(Amazon). I paid $14 for the new manifold bypass valve. $42 for thermal regulator(eBay). All prices are included shipping and there was no tax. I have around 8-12 hours total of isolating, cleaning and replacing defective parts. Slow, I know, because I learned as I went along. I piece milled knowledge I gained from watching a few really old you tube videos, got the general idea of how everything worked and fixed things myself. I never hired any professional pool repairman, so I dont know what they would charge in labor, but I can't imagine it would be cost effective to repair this stuff if you don't do the labor yourself. I hear they run $120/hr. I felt this heater was too easy to work on for that kind of money, so I did repairs myself. Cheers!

[@peterphelps7969]

@@pvt-pilot I thought you were a service tech at first you give some great information. We get $75.00 / hr for a tech and helper but we're in the mountains of Asheville so the demand is less than in your area.Cheers!

[@benthompson1962]

Any chance you have the exact parts list you ordered so I don't get the wrong items? you stated $99 for sensors from Amazon. I just wanted to make sure I go the right stuff. Thanks.

[@pvt-pilot]

@@benthompson1962 sorry for the late response. Check this out at Amazon.com Optimum Pool Technologies Heater Repair Kit for Pentair MasterTemp & Max-E-Therm - Replacement Thermistors & Switches www.amazon.com/dp/B072B5VTGC/ref=cm_sw_r_other_apa_i_XQTEEbKDP8XTB

[@juanaguirre696]

Do you have any idea what is could be, when mastertemp 400 is turned on and instantly turns service system on? Blower not motor blows or turns

[@pvt-pilot]

Yes sir, when you turn on Pentair heaters, they initialize with "service heater" light on and AFS light on. Both lights will stay on momentarily until the blower motor turns on and blows hard enough to close the AFS (Air Flow Switch). Once the AFS closes, the diagnostic LED will go out which also should turn off your "service heater" light. This is normal operating boot up procedure. Since you say your blower motor is not blowing, your AFS will never close, so your "service heater" light will continue to stay on and your heater will not continue booting up. You need to isolate the trouble that is causing your blower motor to fail. Check for voltage on the motors power wires when it is trying to boot up. If you have voltage, check for obstructions in the fan. If it is clean, spin the fan to see if it is a seized motor. You might be able to spin it free. I had to hand spin mine one season about 5 years ago. If you have voltage on motor's power wires and nothing else works to get it spinning, you will need to replace the motor.

[@officerkrupke4966]

Check water pressure switch and high limit sensor. Both should read 0 ohms resistance with pool pump running.

[@ernesttorres4059]

It is a very expensive repair and in the end, you still have an old heater.

[@robsanchez5742]

Finding flakes of corrosion and encrusted salt with specks of "green" copper(?) in the spa section of the pool. Is that a tell tale for a future leak or is it just salt scale? (salt water pool, 250 MasterTemp Serial 1119094180019N).

[@pvt-pilot]

Yeah, the only metal in your entire system that the water touches is the insides of the copper tubes of the heat exchanger in the video. Everything else is plastic including the main pump's impeller. So, the heater is the supplier of the flakes and it is located after the filter in the normal flow of water to the pool. This makes for an express delivery of garbage in your heater to your spa. You likely have scale and/or corrosion on the inside of the copper tubing. You could pull them out and pressure wash the insides of each tube 1 tube at a time and hope for a few more years of service, but if you go through all of that trouble, I would just replace them with new assembly.

[@seanfagan4996]

They should be built like a boiler what crap.

[@Michaelzeiss]

How much did that coil cost?

[@pvt-pilot]

Back then, I got mine on eBay for $599 to the door (free shipping and no out of state sales tax back then) Here it is on Amazon: www.amazon.com/dp/B004VTGDL6/ref=cm_sw_r_cp_apa_glt_fabc_H0QASK8Z0MQCV6HSYJQW To make matters worse, this doesn't even come with the new white thermal insulating pads. Mine did.

[@aaabbbccc543]

the whole thing should be copper and stainless steel.... anything else is just crap